The http/cgi package now supports both being
a CGI host or being a CGI child process.

R=rsc, adg, bradfitzwork
CC=golang-dev
https://golang.org/cl/4245070

to the receiver. Remove lots of TODOS.

R=rsc
CC=golang-dev
https://golang.org/cl/4257057

"standard output" should have been "standard error".  Sorry about that..

R=adg
CC=golang-dev
https://golang.org/cl/4240088

R=bradfitzgo, rsc, bradfitzwork
CC=golang-dev
https://golang.org/cl/4235056

R=adg
CC=golang-dev
https://golang.org/cl/4258041

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/4254061

Fixes #1586.

R=ken2
CC=golang-dev
https://golang.org/cl/4244057

Added example of a return statement w/o expressions
in a function with a _ result parameter.

See also: http://code.google.com/p/go/issues/detail?id=1586

R=rsc, r, iant
CC=golang-dev
https://golang.org/cl/4266049

R=rsc, dsymonds
CC=golang-dev
https://golang.org/cl/4250063

R=rsc
CC=golang-dev
https://golang.org/cl/4239066

R=rsc
CC=golang-dev
https://golang.org/cl/4252063

Change unsafe.Pointer to be its own kind of
type, instead of making it equivalent to *any.
The change complicates import and export
but avoids the need to find all the places that
operate on pointers but should not operate on
unsafe.Pointer.

Fixes #1566. (a different way)
Fixes #1582.

R=ken2
CC=golang-dev
https://golang.org/cl/4264050

Still to do: **T.

R=rsc
CC=golang-dev
https://golang.org/cl/4247061

net.Conn is itself a io.ReadWriteCloser, so
most code should be unaffected.

R=rsc, gburd
CC=golang-dev
https://golang.org/cl/4261052

Was only breaking on some dashboard builds because
not all run the network tests.

R=bradfitzgo, bradfitzwork
CC=golang-dev
https://golang.org/cl/4240086

The parser populates all scopes for a given file (except
type-related scopes for structs, interfaces, and methods
of types) at parse time.

A new parser flag, DeclarationErrors, enables error messages
related to declaration errors (as far as it is possible to
provide them).

The resulting AST has all (non-field, non-method) identifiers
resolved that can be resolved w/o doing imports or parsing
missing package files.

The ast.File node contains the (partially complete)
package scope and a list of unresolved global identifiers.

All type-specific data structures have been removed from the AST.

The existing typechecker is functional but needs to be adjusted
(simplified) accordingly. Utility functions to resolve all
identifiers for a package (after handling imports and parsing
all package files) are  missing.

Unrelated changes:
- Rename typechecker/testdata files to that they are not considered
  by gofmt.
- Minor cleanups/simplifications.

Parses all .go files in src and misc without declaration errors.
Runs all tests. Changes do not affect gofmt output.

R=rsc
CC=golang-dev
https://golang.org/cl/4244049

R=r, adg
CC=golang-dev
https://golang.org/cl/4256052

As a data point, this enables goinstall to handle the standard
syscall package almost unchanged (there's one file with the _bsd
extension, and a .c file which isn't supposed to be compiled in).

R=rsc
CC=golang-dev
https://golang.org/cl/4259057

In June 2010 I accidentally checked in pending
changes to package rpc in a compiler CL:
https://golang.org/cl/1736041

I backed them out by hand in a followup CL:
https://golang.org/cl/1736042

That followup CL missed the lines being deleted
in this CL, spotted by Petar.

hg diff -r 5678:5683 src/cmd/prof/gopprof \
        src/pkg/image/png/reader.go \
        src/pkg/rpc/client.go \
        src/pkg/rpc/jsonrpc/all_test.go \
        src/pkg/rpc/jsonrpc/server.go \
        src/pkg/rpc/server.go \
        test/arm-pass.txt

confirms that these lines in server.go are the
only ones that were missed by the original followup.

Fixes #1583.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/4266046

As a data point, with this change goinstall is able to
fully build package big out of the box.

R=rsc
CC=golang-dev
https://golang.org/cl/4264049

R=rsc, bradfitzwork
CC=golang-dev
https://golang.org/cl/4235055

TBR=brainman
CC=golang-dev
https://golang.org/cl/4237060

func init runs *after* var declarations

TBR=niemeyer
CC=golang-dev
https://golang.org/cl/4260055

R=agl1, rsc
CC=golang-dev
https://golang.org/cl/4257042

This enables goinstall to handle .go and .c files (for cgo)
which are named after the following patterns:

    name_$(GOOS).*
    name_$(GOARCH).*
    name_$(GOOS)_$(GOARCH).*

Files with those names are only included if the $(GOOS) and
$(GOARCH) match the current system.

R=rsc
CC=golang-dev
https://golang.org/cl/4172055

* Change use of m->g0 stack (aka scheduler stack).
* Provide runtime.mcall(f) to invoke f() on m->g0 stack.
* Replace scheduler loop entry with runtime.mcall(schedule).

Runtime.mcall eliminates the need for fake scheduler states that
exist just to run a bit of code on the m->g0 stack
(Grecovery, Gstackalloc).

The elimination of the scheduler as a loop that stops and
starts using gosave and gogo fixes a bad interaction with the
way cgo uses the m->g0 stack.  Cgo runs external (gcc-compiled)
C functions on that stack, and then when calling back into Go,
it sets m->g0->sched.sp below the added call frames, so that
other uses of m->g0's stack will not interfere with those frames.
Unfortunately, gogo (longjmp) back to the scheduler loop at
this point would end up running scheduler with the lower
sp, which no longer points at a valid stack frame for
a call to scheduler.  If scheduler then wrote any function call
arguments or local variables to where it expected the stack
frame to be, it would overwrite other data on the stack.
I realized this possibility while debugging a problem with
calling complex Go code in a Go -> C -> Go cgo callback.
This wasn't the bug I was looking for, it turns out, but I believe
it is a real bug nonetheless.  Switching to runtime.mcall, which
only adds new frames to the stack and never jumps into
functions running in existing ones, fixes this bug.

* Move cgo-related code out of proc.c into cgocall.c.
* Add very large comment describing cgo call sequences.
* Simpilify, regularize cgo function implementations and names.
* Add test suite as misc/cgo/test.

Now the Go -> C path calls cgocall, which calls asmcgocall,
and the C -> Go path calls cgocallback, which calls cgocallbackg.

The shuffling, which affects mainly the callback case, moves
most of the callback implementation to cgocallback running
on the m->curg stack (not the m->g0 scheduler stack) and
only while accounted for with $GOMAXPROCS (between calls
to exitsyscall and entersyscall).

The previous callback code did not block in startcgocallback's
approximation to exitsyscall, so if, say, the garbage collector
were running, it would still barge in and start doing things
like call malloc.  Similarly endcgocallback's approximation of
entersyscall did not call matchmg to kick off new OS threads
when necessary, which caused the bug in issue 1560.

Fixes #1560.

R=iant
CC=golang-dev
https://golang.org/cl/4253054

No known bugs in the current pipe,
but this one is simpler and easier to
understand.

R=iant
CC=golang-dev
https://golang.org/cl/4252057

R=golang-dev, rsc1, rsc
CC=golang-dev
https://golang.org/cl/4253060

R=rsc
CC=golang-dev
https://golang.org/cl/4268041

R=rsc
CC=golang-dev
https://golang.org/cl/4240082

R=adg
CC=golang-dev
https://golang.org/cl/4245065

R=adg, rsc
CC=Joe Poirier, golang-dev
https://golang.org/cl/4257052

R=bradfitzgo, dsymonds
CC=golang-dev
https://golang.org/cl/4244053

R=rsc
CC=golang-dev
https://golang.org/cl/4250061

The Hijack functionality wasn't removed, but now you have
to test if your ResponseWriter is also a Hijacker:

func ServeHTTP(rw http.ResponseWriter, req *http.Request) {
    if hj, ok := rw.(http.Hijacker); ok {
        hj.Hijack(..)
    }
}

R=rsc
CC=golang-dev
https://golang.org/cl/4245064

R=rsc
CC=golang-dev
https://golang.org/cl/4264048

R=r, rsc, dfc
CC=golang-dev
https://golang.org/cl/4240081

R=niemeyer
CC=golang-dev
https://golang.org/cl/4256057

R=golang-dev, rsc1
CC=golang-dev
https://golang.org/cl/4235054

R=rsc
CC=golang-dev
https://golang.org/cl/4253058