Feature extraction was tested before, but not the final diffs.

This CL breaks function main into a smaller main + testable
compareAPI.

No functional changes.

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/6820057

API change.

R=golang-dev, dsymonds, nigeltao, rsc, r
CC=golang-dev
https://golang.org/cl/6760045

On 6g/linux:
benchmark                     old ns/op    new ns/op    delta
BenchmarkFDCT                      4606         4241   -7.92%
BenchmarkIDCT                      4187         3923   -6.31%
BenchmarkDecodeBaseline         3154864      3170224   +0.49%
BenchmarkDecodeProgressive      4072812      4017132   -1.37%
BenchmarkEncode                39406920     34596760  -12.21%

Stack requirements before (from 'go tool 6g -S'):
(scan.go:37) TEXT    (*decoder).processSOS+0(SB),$1352-32
(writer.go:448) TEXT    (*encoder).writeSOS+0(SB),$5344-24

after:
(scan.go:37) TEXT    (*decoder).processSOS+0(SB),$1064-32
(writer.go:448) TEXT    (*encoder).writeSOS+0(SB),$2520-24

Also, in encoder.writeSOS, re-use the yBlock scratch buffer for Cb and
Cr. This reduces the stack requirement slightly, but also avoids an
unlucky coincidence where a BenchmarkEncode stack split lands between
encoder.writeByte and bufio.Writer.WriteByte, which occurs very often
during Huffman encoding and is otherwise disasterous for the final
benchmark number. FWIW, the yBlock re-use *without* the s/int/int32/
change does not have a noticable effect on the benchmarks.

R=r
CC=golang-dev, rsc
https://golang.org/cl/6823043

"JSON object" means something specific, which
isn't the case here.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6789044

Fixes #4306.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/6816054

Fix the problem with no cookie handling when sending
other than GET or HEAD request through
(*Client) Do(*Request) (*Resposne, error).
https://code.google.com/p/go/issues/detail?id=3985

Adds a function (*Client) send(*Request) (*Reponse, error):
- sets cookies from CookieJar to request,
- sends request
- parses a reply cookies and updates CookieJar

Fixes #3985

R=bradfitz
CC=gobot, golang-dev
https://golang.org/cl/6653049

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6820049

RFC 5280 section 4.1.2.5.1 says so.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6775068

Previously we converted a time to UTC *and* serialized the timezone of
the original time. With this change, we serialize a UTCTime in the
original timezone.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6817048

- make sure dclcontext == PAUTO only in function bodies
- introduce PDISCARD to discard declarations in bodies of repeated imports
- skip printing initializing OAS'es in export mode, assuming they only occur after ODCL's
- remove ODCL and the initializing OAS from inl.c:ishairy
- fix confused use of ->typecheck in typecheckinl: it's about the ->inl, not about the fn.
- debuging aids: print ntype on ONAMEs too and -Emm instead of -Ell.

fixes #2812

R=rsc
CC=golang-dev
https://golang.org/cl/6800043

includes step 0: synthesize outparams, from 6600044
includes step 1,2: give outparams loopdepth 0 and verify unchanged results
         generate esc:$mask tags, but still tie to sink if a param has mask != 0
from 6610054

adds final steps:
- have esccall generate n->escretval, a list of nodes the function results flow to
- use these in esccall and ORETURN/OAS2FUNC/and f(g())
- only tie parameters to sink if tag is absent, otherwise according to mask, tie them to escretval

R=rsc, bradfitz
CC=dave, gobot, golang-dev, iant, rsc
https://golang.org/cl/6741044

The "did_ftplugin" lines were ineffective and the "K" mapping was too
invasive, which is why it was removed.

R=golang-dev, dsymonds, minux.ma
CC=golang-dev
https://golang.org/cl/6823044

R=golang-dev, bradfitz
CC=andrey.radev, golang-dev
https://golang.org/cl/6775067

Too many people quote entire emails and put their reply at the top ("top posting"),
so we shouldn't recognise review commands anywhere in the review text.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6815048

It is essentially identical to the version in 6g.

R=dave, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6710043

R=golang-dev, fullung, dave, minux.ma
CC=golang-dev
https://golang.org/cl/6682046

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6777066

Before this patch the test would close the file descriptor but
not the os.File.  When the os.File was GC'ed, the finalizer
would close the file descriptor again.  That would cause
problems if the same file descriptor were returned by a later
call to open in another test.

On my system:

> GOGC=30 go test
--- FAIL: TestPassFD (0.04 seconds)
passfd_test.go:62: 	FileConn: dup: bad file descriptor
FAIL

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6776053

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/6762051

setAddr was showing up in profiles due to string concatenation construction the os.File name field. netFD.sysfile's Name() is never used, except in dup() so I believe it is safe to avoid this allocation.

R=mikioh.mikioh, rsc
CC=golang-dev
https://golang.org/cl/6742058

Thanks to Minux and Remy for their advice.

The EOR optimisation is applied to a few places in the stdlib.

// hash/crc32/crc32.go
func update(crc uint32, tab *Table, p []byte) uint32 {
	crc = ^crc
	for _, v := range p {
        	crc = tab[byte(crc)^v] ^ (crc >> 8)
	}
	return ^crc
}

before:

--- prog list "update" ---
0164 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:101) TEXT        update+0(SB),$12-24
0165 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:101) MOVW        tab+4(FP),R8
0166 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:102) MOVW        crc+0(FP),R0
0167 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:102) EOR         $-1,R0,R5
0168 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:103) MOVW        p+8(FP),R0
0169 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:103) MOVW        R0,autotmp_0019+-12(SP)

after:

--- prog list "update" ---
0164 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:101) TEXT        update+0(SB),$12-24
0165 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:101) MOVW        tab+4(FP),R8
0166 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:102) MOVW        crc+0(FP),R0
0167 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:102) MVN         R0,R5
0168 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:103) MOVW        p+8(FP),R0
0169 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:103) MOVW        R0,autotmp_0019+-12(SP)

After 5l has done its work,

        crc = ^crc
   3d710:       e59d0014        ldr     r0, [sp, #20]
   3d714:       e3e0b000        mvn     fp, #0
   3d718:       e020500b        eor     r5, r0, fp

becomes

        crc = ^crc
   3d710:       e59d0014        ldr     r0, [sp, #20]
   3d714:       e1e05000        mvn     r5, r0

The MOVB optimisation has a small impact on the stdlib, in strconv
and gzip.

// GZIP (RFC 1952) is little-endian, unlike ZLIB (RFC 1950).
func put2(p []byte, v uint16) {
        p[0] = uint8(v >> 0)
        p[1] = uint8(v >> 8)
}

before:

--- prog list "put2" ---
1369 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:76) TEXT       put2+0(SB),$0-16
1370 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:76) MOVHU      v+12(FP),R4
1371 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVHU      R4,R0
1372 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVHU      R0,R0
1373 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVBU      R0,R1
1374 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVBU      R1,R3
1375 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVW       $p+0(FP),R1

after:

--- prog list "put2" ---
1369 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:76) TEXT       put2+0(SB),$0-16
1370 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:76) MOVHU      v+12(FP),R4
1371 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVHU      R4,R0
1372 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVBU      R0,R1
1373 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVBU      R1,R3
1374 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVW       $p+0(FP),R1

R=remyoudompheng, rsc, minux.ma
CC=golang-dev
https://golang.org/cl/6674048

Fixes #4282.

R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6759052

Fixes #4275.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6759053

Used to print:
../test/torture.go:116: internal compiler error: bad width: 0463 (../test/torture.go:116) MOVB    ,BX (0, 8)

R=nigeltao, rsc
CC=golang-dev
https://golang.org/cl/6736068

- Allow secondary values below the default value in second form. This is
  to support before tags for secondary values, as used by Chinese.
- Eliminate collation elements that are guaranteed to be immaterial
  after a weight increment.

R=r
CC=golang-dev
https://golang.org/cl/6739051

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6763043

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6743059

different indexes for values and index blocks. Fixes many regressions.

R=r
CC=golang-dev
https://golang.org/cl/6737057

R=r
CC=golang-dev
https://golang.org/cl/6752043

R=r
CC=golang-dev
https://golang.org/cl/6749058

Also defend our symbol prefixes (now just "go" and "type")
from use as import paths.

Fixes #4257.

R=ken2
CC=golang-dev
https://golang.org/cl/6744072

R=dvyukov
CC=golang-dev
https://golang.org/cl/6733058

Also:
- type-checking receivers
- get rid of some multiple errors at the same position

R=rsc, minux.ma
CC=golang-dev
https://golang.org/cl/6709061

Fixes #4097.

R=rsc
CC=golang-dev, gri
https://golang.org/cl/6749059

R=golang-dev, rsc
CC=0xe2.0x9a.0x9b, golang-dev
https://golang.org/cl/6742063

includes step 0: synthesize outparams, from 6600044
step 1: give outparams loopdepth 0 and verify unchanged results
step 2: generate esc:$mask tags, but still tie to sink if a param has mask != 0
next step: use in esccall (and ORETURN with implicit OAS2FUNC) to avoid tying to sink

R=rsc
CC=golang-dev
https://golang.org/cl/6610054

cmd/gc: track parameter flow, step 0: synthesize name nodes for anonymous PPARAMOUTs without breaking anything.

further work on parameter flow tracking for escape analysis depends on this.

R=rsc
CC=golang-dev
https://golang.org/cl/6600044

in typecheck and walk, conversion from OAS2RECV to OAS2
and to OSELRECV2 duplicated the ->rlist->n to ->right
thereby destroying the strict tree-ness of the AST (up to
ONAMES) of course.  Several recursions in esc.c and inl.c
and probably elsewhere assume nodes of the tree aren't duplicated.
rather than defensively code around this, i'd rather assert
these cases away and fix their cause.

(this was tripped in 6741044)

R=rsc
CC=golang-dev
https://golang.org/cl/6750043

It's common to use the go list command in shell scripts, but
currently it's awkward to print a string slice from the Package
type in a way that's easily parseable by the shell.  For example:

        go list -f '{{range .Deps}}{{.}}
        {{end}}'

(and even that prints an unwanted new line at the end|).

To make this easier, this CL adds a "join" function to the
format template.

        go list -f '{{join .Deps "\n"}}'

R=rsc, dsymonds, minux.ma, remyoudompheng, r
CC=golang-dev
https://golang.org/cl/6680044

Fixes #4230.

R=golang-dev, rsc
CC=golang-dev, remy
https://golang.org/cl/6640056