undo CL 7301062 / 9742f722b558

broke arm garbage collector

traceback_arm fails with a missing pc. It needs CL 7494043.
But that only makes the build break later, this time with
"invalid freelist". Roll back until it can be fixed correctly.

««« original CL description
runtime: restrict stack root scan to locals and arguments

R=rsc
CC=golang-dev
https://codereview.appspot.com/7301062
»»»

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7493044
doc/effective_go.html: update slices and maps.
Drop the phrase "reference types", which has caused confusion.
Add a section about 2D arrays, a common newbie question.

R=golang-dev, cespare, adg, rsc
CC=golang-dev
https://codereview.appspot.com/7423051
cmd/vet: change some warnings to errors for consistency.
Fixes issue 4980.

R=golang-dev, rsc, dsymonds
CC=golang-dev
https://codereview.appspot.com/7479044
vet: check for useless assignments.

The only check so far is for self-assignments of the form "expr = expr",
but even that found one instance in the standard library.

R=r, adg, mtj, rsc
CC=golang-dev
https://codereview.appspot.com/7455048
image/jpeg: for progressive JPEGs, the first SOS segment doesn't
necessarily contain all components.

Fixes issue 4975.

R=r, minux.ma, bradfitz
CC=golang-dev
https://codereview.appspot.com/7469043
net/http: close TCP connection on Response.Body.Close

Previously the HTTP client's (*Response).Body.Close would try
to keep reading until EOF, hoping to reuse the keep-alive HTTP
connection, but the EOF might never come, or it might take a
long time. Now we immediately close the TCP connection if we
haven't seen EOF.

This shifts the burden onto clients to read their whole response
bodies if they want the advantage of reusing TCP connections.

In the future maybe we could decide on heuristics to read some
number of bytes for some max amount of time before forcefully
closing, but I'd rather not for now.

Statistically, touching this code makes things regress, so I
wouldn't be surprised if this introduces new bugs, but all the
tests pass, and I think the code is simpler now too. Maybe.

Please test your HTTP client code before Go 1.1.

Fixes issue 3672

R=golang-dev, adg
CC=golang-dev
https://codereview.appspot.com/7419050
effective_go.html: round 3 of minor edits.

R=golang-dev, iant
CC=golang-dev
https://codereview.appspot.com/7489044
api: update next.txt

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/7518044
misc/emacs: Add compatibility for GNU Emacs 23 and XEmacs >=21.5.32

This CL adds compatibility for GNU Emacs 23 (fixing fontification
issues) and XEmacs >=21.5.32 (fixing a lot of issues). Earlier
versions of XEmacs will not be supported because they do not
support POSIX character classes. Because of that, we also make use
of a lot of functions that were added in 21.5.32.

A known and currently unfixable issue with XEmacs is that go-mode
will not always fontify identifiers that use unicode correctly.

All changes for XEmacs are annotated in the diff.

Note: go--position-bytes is not currently used anywhere, but will
be in a future CL.

Fixes issue 4927.

R=golang-dev, adonovan, cw, patrick.allen.higgins, sameer
CC=golang-dev
https://codereview.appspot.com/7456051

Committer: Alan Donovan <adonovan@google.com>
runtime: change amd64 startup convention

Now the default startup is that the program begins at _rt0_amd64_$GOOS,
which sets DI = argc, SI = argv and jumps to _rt0_amd64.

This makes the _rt0_amd64 entry match the expected semantics for
the standard C "main" function, which we can now provide for use when
linking against a standard C library.

R=golang-dev, devon.odell, minux.ma
CC=golang-dev
https://codereview.appspot.com/7525043
misc/cgo/test: do not stop on first error

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7529043
libmach: fix amd64 pe handling

Fixes issue 4841.

R=golang-dev, rsc
CC=golang-dev
https://codereview.appspot.com/7475046

Committer: Russ Cox <rsc@golang.org>
runtime,misc/cgo/test: disable broken tests so we can test the rest

R=golang-dev, minux.ma
CC=golang-dev
https://codereview.appspot.com/7486048

Committer: Russ Cox <rsc@golang.org>
A+C: Ewan Chou (individual CLA)

Generated by addca.

R=gobot
CC=golang-dev
https://codereview.appspot.com/7473047
strings: remove allocations in Split(s, "")

BenchmarkSplit1     77984460     24131380  -69.06%

R=golang-dev, rsc, minux.ma, dave, extemporalgenome
CC=golang-dev
https://codereview.appspot.com/7458043

Committer: Russ Cox <rsc@golang.org>