net: fix test data corruption in repetitive test runs by -cpu

This CL avoids test data sharing in repetitive test runs;
e.g., go test net -cpu=1,1,1

R=golang-dev, fullung, bradfitz
CC=golang-dev
https://codereview.appspot.com/8011043
runtime: does not report duplicate errors in netpoll
Prevents storm of error messages if something goes wrong.
In the case of issue 5073 the epoll fd was closed by the test.
Update issue 5073.

R=golang-dev, r, rsc
CC=golang-dev
https://codereview.appspot.com/7966043
doc: fix typo in go 1.1 doc

R=golang-dev, iant
CC=golang-dev
https://codereview.appspot.com/7725049
doc/go1.1.html: describe Zone and other net changes
Mild adaptation of rsc's 8021043, which I was unable to clpatch.
(rsc is offline)

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7741049
builtin: add linkable-to declarations for iota and nil
Aids godoc.

R=golang-dev, gri, bradfitz
CC=golang-dev
https://codereview.appspot.com/7992044
godoc: link identifiers to declarations

The changes are almost completely self-contained
in the new file linkify.go. The other changes are
minimal and should not disturb the currently
working godoc, in anticipation of Go 1.1.

To disable the feature in case of problems, set
-links=false.

Fixes issue 2063.

R=adg, r
CC=golang-dev
https://codereview.appspot.com/7883044
runtime: ensure forward progress when unwinding an arm stack frame

The arm gentraceback mishandled frame linkage values pointing
to the assembly return function.  This function is special as
its frame size is zero and it contains only one instruction.
These conditions would preserve the frame pointer and result
in an off by one error when unwinding the caller.

Fixes issue 5124

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/8023043
doc/go1.1.html: net/mail, net/smtp

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7835049
reflect: add garbage collection info in ChanOf, MapOf, PtrTo, SliceOf

ArrayOf will remain unexported (and therefore unused) for Go 1.1.

Fixes issue 4375.

R=0xe2.0x9a.0x9b, r, iant
CC=golang-dev
https://codereview.appspot.com/7716048

Committer: Rob Pike <r@golang.org>
godoc: internal cleanup: remove a TODO

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/8005044
pkg/runtime: ignore runtime.memlimit when allocating heap

For Go 1.1, stop checking the rlimit, because it broke now
that mheap is allocated using SysAlloc.  See issue 5049.

R=r
CC=golang-dev
https://codereview.appspot.com/7741050
doc: consistent path names in example

Always use /home/you for $HOME in examples.

Trivial enough that someone else can integrate this change if they are editing go1.1.html

R=r
CC=golang-dev
https://codereview.appspot.com/8025043
cmd/gc: enable racewalk of HMUL nodes.

A HMUL node appears in some constant divisions, but
to observe a false negative in race detector the divisor must be
suitably chosen to make sure the only memory access is
done for HMUL.

R=dvyukov
CC=golang-dev
https://codereview.appspot.com/7935045
lib/codereview/codereview.py: fix crash when hg gofmt has no files
The gofmt function was returning a string, which isn't the right type.
Three cheers for dynamic typing.

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7917044
godoc: pass *PageInfos instead of *token.FileSets in templates

- convert all formatters that require a *token.FileSet to
  consistenly use a *PageInfo as first argument instead
- adjust templates correspondingly
- fix outstanding bug from previous CL 8005044

Going forward, with this change the affected functions have
access to the full page "context" (PageInfo), not just the
respective file set. This will permit better context-dependent
formatting in the future.

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7860049
net/textproto: add "Cookie" to the common headers list

Seems to have been omitted before.

R=golang-dev, dave
CC=golang-dev
https://codereview.appspot.com/7749049