* Maintain Sym* list for text with individual
  prog lists instead of using one huge list and
  overloading p->pcond.
* Comment what each file is for.
* Move some output code from span.c to asm.c.
* Move profiling into prof.c, symbol table into symtab.c.
* Move mkfwd to ld/lib.c.
* Throw away dhog dynamic loading code.
* Throw away Alef become.
* Fix printing of WORD instructions in 5l -a.

Goal here is to be able to handle each piece of text or data
as a separate piece, both to make it easier to load the
occasional .o file and also to make it possible to split the
work across multiple threads.

R=ken2, r, ken3
CC=golang-dev
https://golang.org/cl/2335043

This is entirely adding and removing tabs.
It looks weird but will make the diffs for the
next change easier to read.

R=ken2
CC=golang-dev
https://golang.org/cl/2490041

R=rsc
CC=golang-dev
https://golang.org/cl/2485041

R=rsc
CC=golang-dev
https://golang.org/cl/2472041

R=r, r2
CC=golang-dev
https://golang.org/cl/2469041

Use a bytes.Buffer in log writing instead of string concatenation.
Should reduce the number of allocations significantly.

R=rsc, r2
CC=golang-dev
https://golang.org/cl/2417042

R=adg
CC=golang-dev
https://golang.org/cl/2468041

R=r, r2, rsc, uriel
CC=golang-dev
https://golang.org/cl/2433042

Fixes some race conditions.

R=r
CC=golang-dev
https://golang.org/cl/2456041

6l was skipping emitting the (2 byte) symbol table if there were no imported or exported
symbols. You can't just drop the symbol table entirely - the linker dies if you have
a linkedit section but no table. You can omit the linkedit section or both the linkedit
and the dlyd parts in the right circumstances, but that seems much more risky to me.

R=rsc
CC=golang-dev
https://golang.org/cl/2421042

New logging interface simplifies and generalizes.

1) Loggers now have only one output.
2) log.Stdout, Stderr, Crash and friends are gone.
	Logging is now always to standard error by default.
3) log.Panic* replaces log.Crash*.
4) Exiting and panicking are not part of the logger's state; instead
	the functions Exit* and Panic* simply call Exit or panic after
	printing.
5) There is now one 'standard logger'.  Instead of calling Stderr,
	use Print etc.  There are now triples, by analogy with fmt:
		Print, Println, Printf
	What was log.Stderr is now best represented by log.Println,
	since there are now separate Print and Println functions
	(and methods).
6) New functions SetOutput, SetFlags, and SetPrefix allow global
	editing of the standard logger's properties.   This is new
	functionality. For instance, one can call
		log.SetFlags(log.Lshortfile|log.Ltime|log.Lmicroseconds)
	to get all logging output to show file name, line number, and
	time stamp.

In short, for most purposes
	log.Stderr -> log.Println or log.Print
	log.Stderrf -> log.Printf
	log.Crash -> log.Panicln or log.Panic
	log.Crashf -> log.Panicf
	log.Exit -> log.Exitln or log.Exit
	log.Exitf -> log.Exitf (no change)

This has a slight breakage: since loggers now write only to one
output, existing calls to log.New() need to delete the second argument.
Also, custom loggers with exit or panic properties will need to be
reworked.

All package code updated to new interface.

The test has been reworked somewhat.

The old interface will be removed after the new release.
For now, its elements are marked 'deprecated' in their comments.

Fixes #1184.

R=rsc
CC=golang-dev
https://golang.org/cl/2419042

R=ken2
CC=golang-dev
https://golang.org/cl/2465041

R=adg
CC=golang-dev
https://golang.org/cl/2404043

R=rsc, albert.strasheim
CC=golang-dev
https://golang.org/cl/2356042

R=brainman, rsc, kardia, Joe Poirier
CC=golang-dev
https://golang.org/cl/1910041

Effectively reverts https://code.google.com/p/go/source/detail?r=8c52477401ad
Should make ARM build pass again, but untested.
Probably still bugs involving reflect.call somewhere.

R=ken2
CC=golang-dev
https://golang.org/cl/2416042

R=adg
TBR=adg
CC=golang-dev
https://golang.org/cl/2449041

R=adg
CC=golang-dev
https://golang.org/cl/2448041

Make ColorImage methods' receiver type be a pointer.

R=r, rsc
CC=golang-dev
https://golang.org/cl/2345043

The linker doesn't support multiple object files (maybe it did in the past?)

R=rsc
CC=golang-dev
https://golang.org/cl/2444041

Package iterable has outlived its utility.

It is an interesting demonstration, but it encourages
people to use iteration over channels where simple
iteration over array indices or a linked list would be
cheaper, simpler, and have fewer races.

R=dsymonds, r
CC=golang-dev
https://golang.org/cl/2436041

R=rsc
CC=golang-dev
https://golang.org/cl/2443041

Fixes #1175.

R=lvd
CC=golang-dev
https://golang.org/cl/2439041

An exercise in reflection and an unusual tool.

From the usage message:

usage: gotry [packagedirectory] expression ...
Given one expression, gotry attempts to evaluate that expression.
Given multiple expressions, gotry treats them as a list of arguments
and result values and attempts to find a function in the package
that, given the first few expressions as arguments, evaluates to
the remaining expressions as results.  If the first expression has
methods, it will also search for applicable methods.

If there are multiple expressions, a package directory must be
specified. If there is a package argument, the expressions are
evaluated in an environment that includes
	import . "packagedirectory"

Examples:
	gotry 3+4
		# evaluates to 7
	gotry strings '"abc"' '"c"' 7-5
		# finds strings.Index etc.
	gotry regexp 'MustCompile("^[0-9]+")' '"12345"' true
		# finds Regexp.MatchString

R=rsc, PeterGo, r2
CC=golang-dev
https://golang.org/cl/2352043

Gob decoding does not overwrite fields which are zero
in the encoder.
Fixes #1174.

R=r, r2
CC=golang-dev
https://golang.org/cl/2337044

Fixes malformed object message from nm etc.
Fixes #1180.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/2390042

Fixes #1177.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/2387042

R=r, r2
CC=golang-dev
https://golang.org/cl/2438041

R=golang-dev, adg, rsc
CC=golang-dev
https://golang.org/cl/2336044

R=Sam
CC=golang-dev
https://golang.org/cl/2437041

        Fixes #1181.

R=rsc, agl1, cw, r2
CC=golang-dev
https://golang.org/cl/2414041

        Fixes #1146.

R=rsc, agl1
CC=golang-dev
https://golang.org/cl/2380042

Permits one to easily put a timeout in a select:

select {
case <-ch:
	// foo
case <-time.After(1e6):
	// bar
}

R=r, rog, rsc, sameer1, PeterGo, iant, nigeltao_gnome
CC=golang-dev
https://golang.org/cl/2321043

R=adg, ehog.hedge
CC=golang-dev
https://golang.org/cl/2385041

stack is off by one if calling
through reflect.Call

R=rsc
CC=golang-dev
https://golang.org/cl/2400041

Auto-detect both if not set, and if GOARCH is not set use GOHOSTARCH.

GOHOSTARCH is used to set the -m32 or -m64 flags for gcc.

This is so that 64-bit can build binaries that run on 32-bit systems.

R=rsc, iant, brainman
CC=golang-dev
https://golang.org/cl/2342045

R=gri, rsc
CC=golang-dev
https://golang.org/cl/2212044

R=ken2
CC=golang-dev
https://golang.org/cl/2390041

Reported by Jeff Allen.

R=r, r2
CC=golang-dev
https://golang.org/cl/2385042

Enables lookup of _jabber._tcp.gmail.com's SRV record.

Fixes #1167.

R=r, r2
CC=golang-dev
https://golang.org/cl/2353043