newTypeEncoder (called once per type and then cached) was
looking at the first value seen of that type's addressability
and caching the encoder decision.  If the first value seen was
addressable and a future one wasn't, it would panic.

Instead, introduce a new wrapper encoder type that checks
CanAddr at runtime.

Fixes #6458

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13839045

And same for UDP.

Fixes #6465.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13740048

Fixes #6455.

R=mikioh.mikioh, rsc
CC=golang-dev
https://golang.org/cl/13457058

Fixes #6460.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13761046

Fixes a bug reported privately.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13846043

Fixes #6347.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13845044

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/13820046

The syntax accepted is full build constraints, not just
GOOS, GOARCH, and GOOS/GOARCH.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13504048

Fixes #6417.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13843043

Fixes #6456.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13740047

Makes build unnecessarily slower. Will fix the parser instead.

««« original CL description
runtime/pprof: run TestGoroutineSwitch for longer

Short test now takes about 0.5 second here.

Fixes #6417.

The failure was also seen on our builders.

R=golang-dev, minux.ma, r
CC=golang-dev
https://golang.org/cl/13321048
»»»

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/13720048

Fix a few minor vet quibbles while I'm here.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13235059

Fixes #6431.

Change suggested by kin.wilson.za.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/13314048

Fixes #6449.

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/13829044

In an indexed verb such as %[3]d, if the index is out of range, don't
skip processing the rest of the verbs. The bug was that the bad
index set a bit for the whole format instead of just the verb.

Ok for 1.2 because this is a bug in a 1.2 feature.

Fixes #6434

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/13632058

doc/go1.2: document that godoc and vet will always be installed to their old locations (not $GOPATH/bin).

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13830043

Fixes #6439.

R=r, minux.ma
CC=golang-dev
https://golang.org/cl/13478045

A number was wrong; adjust as suggested to make things clearer.
Fixes #6452

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/13422046

Date header indicated that it contained GMT time,
however it actually sent local time. Fixed by
converting time to UTC.

Also fixes incorrect comment in appendTime().

Regression since CL 9432046.

R=golang-dev, dave, bradfitz
CC=golang-dev
https://golang.org/cl/13386047

notepadplus can only support some normal golang's hex and imaginary numbers.
it can't detect some special number, eg. 1./1.e/1.i/1+0.1i (omit "0" in ".0").

R=golang-dev, gvdschoot
CC=ajstarks, golang-dev
https://golang.org/cl/13401047

Generated by addca.

R=gobot
CC=golang-dev
https://golang.org/cl/13819045

Fixes #6305.

R=golang-dev, dave, alex.brainman, r
CC=golang-dev
https://golang.org/cl/13359046

Short test now takes about 0.5 second here.

Fixes #6417.

The failure was also seen on our builders.

R=golang-dev, minux.ma, r
CC=golang-dev
https://golang.org/cl/13321048

Fixes #6124

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/13500046

R=r
CC=golang-dev
https://golang.org/cl/13735044

These were bullet points that I had neglected to flesh out.

R=golang-dev, dvyukov
CC=golang-dev
https://golang.org/cl/13816043

The select2.go test assumed that the memory allocated between
its two samplings of runtime.ReadMemStats is strictly
increasing.  To avoid failing the tests when this is not true,
a greater-than check is introduced before computing the
difference in allocated memory.

R=golang-dev, r, cshapiro
CC=golang-dev
https://golang.org/cl/13701046

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13588044

Fixes #5087.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13812043

Fixes issues 6420.

R=ken2
CC=golang-dev
https://golang.org/cl/13703044

The line number alone does not help when the line is
case '~', '*', '(', ')', '[', ']', '{', '}', '?', ':', ';', ',', '*', '%', '^', '!', '=', '<', '>', '+', '-', '&', '|':

R=ken2
CC=golang-dev
https://golang.org/cl/13431046

If a fault happens in malloc, inevitably the next thing that happens
is a deadlock trying to allocate the panic value that says the fault
happened. Stop doing that, two ways.

First, reject panic in malloc just as we reject panic in garbage collection.

Second, runtime.panicstring was using an error implementation
backed by a Go string, so the interface held an allocated *string.
Since the actual errors are C strings, define a new error
implementation backed by a C char*, which needs no indirection
and therefore no allocation.

This second fix will avoid allocation for errors like nil panic derefs
or division by zero, so it is worth doing even though the first fix
should take care of faults during malloc.

Update #6419

R=golang-dev, dvyukov, dave
CC=golang-dev
https://golang.org/cl/13774043

See also issue 6428.

R=r, rsc
CC=golang-dev
https://golang.org/cl/13794043

Fixes #6245.

R=golang-dev, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/13751045

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13775045

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13788043

Looks like the dist tool really doesn't like tags.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13354049

Keeping pointers from the pre-walk phase confuses
the race detection instrumentation.

Fixes #6418.

R=golang-dev, dvyukov, r
CC=golang-dev
https://golang.org/cl/13368057

R=golang-dev, dave, r
CC=golang-dev
https://golang.org/cl/13777043

This will allow us to cut binaries with names like:
        go1.2rc1.darwin-amd64-osx10.6.pkg
        go1.2rc1.darwin-amd64-osx10.8.pkg

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13629045