I fixed this data race regression in two ways: in net/http itself, and also
partially reverting the change from https://golang.org/cl/77580046 .
Previously a Read from a strings.Reader or bytes.Reader returning 0 bytes
would not be a memory write. After 77580046 it was. This reverts that back
in case others depended on that. Also adds tests.

Fixes #7856

LGTM=ruiu, iant
R=iant, ruiu
CC=golang-codereviews, gri
https://golang.org/cl/94740044

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/93750043

Godoc makes it look better this way; before, it all ran together into nonsense.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/90400045

Work around buggy(?) Linux /proc filesystem.

Fixes #7808

LGTM=iant
R=golang-codereviews, iant
CC=adg, golang-codereviews
https://golang.org/cl/90400044

Previously it would panic because of out-of-bound access
if s1 is longer than s2.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/90110043

Fixes #7814.

LGTM=agl, adonovan
R=agl, adonovan
CC=golang-codereviews
https://golang.org/cl/90080043

TestVariousDeadlines1Proc was flaky on my system,
failing on about 5% of runs.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/89830045

LGTM=robert.hencke, iant
R=golang-codereviews, robert.hencke, iant
CC=golang-codereviews
https://golang.org/cl/89760043

LGTM=dvyukov
R=rsc, iant, khr, dvyukov
CC=golang-codereviews
https://golang.org/cl/76520045

Fixes #7829

LGTM=dave
R=golang-codereviews, aram, dave
CC=golang-codereviews
https://golang.org/cl/89830043

Update #7829

LGTM=dave
R=golang-codereviews, dave
CC=golang-codereviews
https://golang.org/cl/89810043

This should have been part of 36eb4a62fbb6,
but I later discovered that addresses are all wrong.
Appropriate test added now.

LGTM=r
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/89470043

Fixes #7331.

LGTM=dave, iant
R=golang-codereviews, dave, gobot, iant
CC=golang-codereviews
https://golang.org/cl/89150043

Update #7331

LGTM=dave, iant
R=golang-codereviews, dave, gobot, iant
CC=golang-codereviews
https://golang.org/cl/89520043

`GOARCH=arm go tool 6c` used to give "<prog>: cannot use 6c with GOARCH=arm"

LGTM=r
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/89330043

CL 89050043 only allows -ccflags for 'go test', this
CL really handles the flag like the other -??flags.
Many thanks to Dobrosław Żybort for pointing this out.
Fixes #7810 (again).

LGTM=iant, matrixik
R=golang-codereviews, iant, matrixik
CC=golang-codereviews
https://golang.org/cl/89230044

LGTM=minux.ma
R=r, minux.ma
CC=golang-codereviews
https://golang.org/cl/89710043

Fixes #7783

LGTM=minux.ma
R=rsc, minux.ma
CC=golang-codereviews
https://golang.org/cl/89290043

Since there is no Runemask constant in UTF-8 enum in
9atom, removing the other constants leads to an empty
enum, which is illegal. Thus, we remove enum entirely.

LGTM=r
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/82660044

Fixes #6973

LGTM=r
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/88820043

following on CL https://golang.org/cl/76810045 and
issue 7563, i now see there's another "remove(outfile)" a few
dozen lines down that also needs fixing.

LGTM=iant
R=golang-codereviews, iant
CC=0intro, golang-codereviews, r
https://golang.org/cl/89030043

LGTM=aram, r
R=r, aram, bradfitz
CC=golang-codereviews, rsc
https://golang.org/cl/89130045

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/89370043

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/89270043

LGTM=r
R=r
CC=golang-codereviews, rsc
https://golang.org/cl/86180046

changed (pwd string) to (dir string), as some think pwd means passwd.
Fixes #7811.

LGTM=iant
R=golang-codereviews, iant, bradfitz
CC=golang-codereviews
https://golang.org/cl/89100043

Fixes #7810.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/89050043

Fixes #5357

LGTM=nigeltao
R=nigeltao
CC=golang-codereviews
https://golang.org/cl/87910050

Patch from msolo. Just moving it to a CL.
The test fails before and passes with the fix.

Fixes #7098

LGTM=msolo, rsc
R=rsc, iant, msolo
CC=golang-codereviews
https://golang.org/cl/88900044

It is possible to use ./ imports on Windows but it
requires some extra command-line work
('go build' does this automatically, but we can't use 'go build' here).

Instead, use an ordinary import and -I/-L, which are easier to use.

LGTM=iant
R=iant
CC=golang-codereviews
https://golang.org/cl/89040043

LGTM=rsc, bradfitz
R=golang-codereviews, rsc, bradfitz
CC=golang-codereviews
https://golang.org/cl/88170049

According to RFC 6265 a cookie value may contain neither
commas nor spaces but such values are very common in the
wild and browsers handle them very well so we'll allow
both commas and spaces.
Values starting or ending in a comma or a space are
sent in the quoted form to prevent missinterpetations.

RFC 6265 conforming values are handled as before and
semicolons, backslashes and double-quotes are still
disallowed.

Fixes #7243

LGTM=nigeltao
R=nigeltao
CC=bradfitz, golang-codereviews
https://golang.org/cl/86050045

The rewrite is due to Rob.

LGTM=r, bradfitz, josharian
R=golang-codereviews, bradfitz, r, josharian
CC=golang-codereviews
https://golang.org/cl/87410043

Fixes #7800.

LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/87790051

Variables declared with 'var' have no sym->def.

Fixes #7794.

LGTM=rsc
R=golang-codereviews, bradfitz, rsc
CC=golang-codereviews
https://golang.org/cl/88360043

Cgo writes C function declarations pretending every arg is a pointer.
If the C function is deferred, it does not inhibit stack copying on split.
The stack copying code believes the C declaration, possibly misinterpreting
integers as pointers.

Probably the right fix for Go 1.3 is to make deferred C functions inhibit
stack copying.

For Go 1.4 and beyond we probably need to make cgo generate Go code
for 6g here, not C code for 6c.

Update #7695

LGTM=khr
R=khr
CC=golang-codereviews
https://golang.org/cl/83820043

Fixes #6364.

LGTM=rsc
R=golang-codereviews, bradfitz, rsc, gobot
CC=golang-codereviews
https://golang.org/cl/13512052

Fixes #7767.

LGTM=rsc
R=golang-codereviews, rsc
CC=golang-codereviews
https://golang.org/cl/87420043

Fixes #7675

LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/85040044

Before the switch to liblink, the linkers accepted the -c flag
to print the call graph. This change restores the functionality.

This came in handy when I was trying to audit the use of SSE
instructions inside the Plan 9 note handler.

LGTM=rsc
R=golang-codereviews, bradfitz, rsc
CC=golang-codereviews
https://golang.org/cl/73990043