cmd/5c, cmd/6c, cmd/8c: isolate textflag and dataflag

Fixes issue 5419.

R=golang-dev, dave, minux.ma, rsc
CC=golang-dev
https://codereview.appspot.com/9241044
misc/pprof: register cnew and runtime.cnewarray as malloc wrappers.

These functions were introduced by revision 139919984600
and should not show up on profiles for consistency.

R=golang-dev, iant
CC=golang-dev
https://codereview.appspot.com/10003043
C: add Will Norris (Google CLA)

R=golang-dev
CC=golang-dev
https://codereview.appspot.com/10019045
build: add intptr typedef for Plan 9

Revision 01810e5c68e9 added the following to src/pkg/runtime/stack.h:

        StackPreempt = (uintptr)(intptr)0xffffade,

The typedef for intptr is defined in two places:

        1. src/pkg/runtime/runtime.h for use by the runtime

        2. include/u.h for use by the compilers and linkers

On Plan 9, we don't use include/u.h but instead augment the host's
u.h with extra typedefs. These are in include/plan9/GOARCH/u.h.

We forgot to add intptr. It didn't cause a problem until now since
that typedef was never used outside the runtime.

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/10023043
cmd/5g, cmd/6g, cmd/8g: remove prototypes for proglist

Each of the backends has two prototypes for this function but
no corresponding definition.

R=golang-dev, bradfitz, khr
CC=golang-dev
https://codereview.appspot.com/9930045
cmd/cc: support 21-bit runes in wide string constants

Changeset 7557a627e9b5 added a temporary stop-gap to silence
a print format warning for %S. This has been reverted.

None of this code is original. It was copied from the latest
Plan 9 compilers.

R=golang-dev, r, rsc
CC=golang-dev
https://codereview.appspot.com/8630044
encoding/asn1: harmonise error prefixes.

This change ensures that error messages always start with "asn1: ".

R=golang-dev, gedimitr
CC=golang-dev
https://codereview.appspot.com/9751043
crypto/tls: support TLS 1.1.

The significant change between TLS 1.0 and 1.1 is the addition of an explicit IV in the case of CBC encrypted records. Support for TLS 1.1 is needed in order to support TLS 1.2.

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7880043
runtime: fix description of SysAlloc

R=golang-dev, iant
CC=golang-dev
https://codereview.appspot.com/10010046
test: do not run SIGCHLD test on Plan 9

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/10017045
image/jpeg: avoid documentation argument over whether it's luma
subsampling or chroma subsampling.

Fixes issue 5569.

R=r
CC=golang-dev
https://codereview.appspot.com/9900044
mime: add support for Plan 9

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/10028043
undo CL 10017045 / 6ec8c49421a0

It was never tested and also breaks Windows.

run.go doesn't yet support the proper !windows,!plan9 syntax.

««« original CL description
test: do not run SIGCHLD test on Plan 9

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/10017045
»»»

R=golang-dev, dave
CC=golang-dev
https://codereview.appspot.com/10024044
Merge branch 'master' into gitfix