so that spawned processes avoid inheriting pipes.

Implement CloseOnExec.
Make file and pipe handles inheritable.

R=rsc, brainman, vincent.vanackere
CC=golang-dev
https://golang.org/cl/4126047

Newer versions of Mercurial require the configuration
of Certification Authorities.

R=rsc
CC=golang-dev
https://golang.org/cl/4128052

Fixes #1452.

R=r
CC=golang-dev
https://golang.org/cl/4023060

Affects receive using := when new variable escapes to heap.

Fixes #1468.

R=ken2
CC=golang-dev
https://golang.org/cl/4119052

readRuner -> runeReader
unreadRuner -> runeUnreader

R=r, rsc
CC=golang-dev
https://golang.org/cl/4000054

Follow morestack, so that crashes during a stack split
give complete traces.  Also mark stack segment boundaries
as an aid to debugging.

Correct various line number bugs with yet another attempt
at interpreting the pc/ln table.  This one has a chance at
being correct, because I based it on reading src/cmd/ld/lib.c
instead of on reading the documentation.

Fixes #1138.
Fixes #1430.
Fixes #1461.

throw: runtime: split stack overflow

runtime.throw+0x3e /home/rsc/g/go2/src/pkg/runtime/runtime.c:78
        runtime.throw(0x81880af, 0xf75c8b18)
runtime.newstack+0xad /home/rsc/g/go2/src/pkg/runtime/proc.c:728
        runtime.newstack()
runtime.morestack+0x4f /home/rsc/g/go2/src/pkg/runtime/386/asm.s:184
        runtime.morestack()
----- morestack called from stack: -----
runtime.new+0x1a /home/rsc/g/go2/src/pkg/runtime/malloc.c:288
        runtime.new(0x1, 0x0, 0x0)
gongo.makeBoard+0x33 /tmp/Gongo/gongo_robot_test.go:344
        gongo.makeBoard(0x809d238, 0x1, 0xf76092c8, 0x1)
----- stack segment boundary -----
gongo.checkEasyScore+0xcc /tmp/Gongo/gongo_robot_test.go:287
        gongo.checkEasyScore(0xf764b710, 0x0, 0x809d238, 0x1)
gongo.TestEasyScore+0x8c /tmp/Gongo/gongo_robot_test.go:255
        gongo.TestEasyScore(0xf764b710, 0x818a990)
testing.tRunner+0x2f /home/rsc/g/go2/src/pkg/testing/testing.go:132
        testing.tRunner(0xf764b710, 0xf763b5dc, 0x0)
runtime.goexit /home/rsc/g/go2/src/pkg/runtime/proc.c:149
        runtime.goexit()

R=ken2, r
CC=golang-dev
https://golang.org/cl/4000053

ReadByter -> ByteReader
ReadRuner -> RuneReader

R=r, r2, rsc
CC=golang-dev
https://golang.org/cl/4023062

Include repository URL in initial mail.
Record repository and base revision in patch description.

R=r
CC=golang-dev
https://golang.org/cl/4126052

R=rsc, rog, r2
CC=golang-dev
https://golang.org/cl/4128049

If the same directory was used for multiple builds,
it was possible for a stale version.go to contain the
wrong definitions for $GOOS and $GOARCH, because
they can change even if the hg version does not.
Split into multiple files to fix.

R=r, r2
CC=golang-dev
https://golang.org/cl/4124050

Fixes #1467.

R=r, r2
CC=golang-dev
https://golang.org/cl/3981054

no semantic change.

R=rsc
CC=golang-dev
https://golang.org/cl/4128048

R=rsc
CC=golang-dev
https://golang.org/cl/4073051

Put it in the same package as ReadByter.
There is no implementation here for either interface.

R=rsc
CC=golang-dev
https://golang.org/cl/4121051

The first two "Literal" tests were silly.
Also fix a naming typo in a couple of tests.

R=rsc
CC=golang-dev
https://golang.org/cl/4127045

R=gri
CC=golang-dev
https://golang.org/cl/4023061

Re-issue to include go/ast fixes for godoc.

R=gri
CC=golang-dev
https://golang.org/cl/3989058

R=adg
CC=golang-dev
https://golang.org/cl/4044048

R=rsc
CC=golang-dev
https://golang.org/cl/4124048

R=rsc
CC=golang-dev
https://golang.org/cl/4119050

Shame on me: I fixed the same bug in 6l in 8691fcc6a66e
(https://golang.org/cl/2609041) and neglected
to look at 5l and 8l to see if they were affected.

On the positive side, the check I added in that CL is the
one that detected this bug.

Fixes #1457.

R=ken2
CC=golang-dev
https://golang.org/cl/3981052

R=ken2
CC=golang-dev
https://golang.org/cl/4001051

- go/ast: introduce SendStmt; adjust SelectStmt
- go/parser: accept new communication syntax, minor
  unrelated cleanups
- go/printer: adjustments for new ast, fewer binary
  expression precedences
- go/token: remove one binary precedence

Adjusted dependent code. gofmt -w src -misc. Ran all tests.

R=rsc, gri
CC=golang-dev
https://golang.org/cl/3989056

There is no log.Crash.

R=r, rsc
CC=golang-dev
https://golang.org/cl/4058048

R=rsc
CC=golang-dev
https://golang.org/cl/4080049

This aligns the naming scheme with the testing package and
also lets govet work on more logging calls.

R=rsc
CC=golang-dev
https://golang.org/cl/4001048

R=rsc
CC=golang-dev
https://golang.org/cl/4119049

These are syntactical changes to better reflect the communication
operator's new status in the language.

- sending to a channel is now done via a send statement
- there is no binary communication operation anymore which
  leads to a reduction of the number of precedence levels
  from 6 to 5 (yeah!)
- small semantic change: since a send operation is not part
  of the expression syntax anymore, a <- send operator is
  binding weaker than any other operator now
- receiving from a channel is done as before via the unary
  receive expression
- communication clauses in select statement now can contain
  send statements or receive expressions

R=rsc, r, iant, ken2, gri1
CC=golang-dev
https://golang.org/cl/3973051

R=r
CC=golang-dev
https://golang.org/cl/4124047

Fixes #1453.

R=ken2
CC=golang-dev
https://golang.org/cl/4125043

R=bradfitzgo, rsc
CC=golang-dev
https://golang.org/cl/4070043

R=gri, josvazg, gri1
CC=golang-dev
https://golang.org/cl/4044047

R=r, gri1
CC=golang-dev
https://golang.org/cl/4092045

Make the error message and the needed action more obvious
when a command isn't found to obtain the source code
of a project.  Users seem to strugle with the existing
wording in practice.

R=rsc
CC=golang-dev
https://golang.org/cl/4058047

Use correct range in allocated register test.

R=rsc, ken2
CC=golang-dev
https://golang.org/cl/4073049

R=rsc
CC=golang-dev
https://golang.org/cl/4042045

The callback mechanism has been made more flexible.
Eliminated one round of argument copying in Syscall.
Faster Get/SetLastError implemented.
Added gettime for gc perf profiling.

R=rsc, brainman, mattn, rog
CC=golang-dev
https://golang.org/cl/4058046

The crypto package is added as a common place to store identifiers for
hash functions. At the moment, the rsa package has an enumeration of
hash functions and knowledge of their digest lengths. This is an
unfortunate coupling and other high level crypto packages tend to need
to duplicate this enumeration and knowledge (i.e. openpgp).

crypto pulls this code out into a common location.

It would also make sense to add similar support for ciphers to crypto,
but the problem there isn't as acute that isn't done in this change.

R=bradfitzgo, r, rsc
CC=golang-dev
https://golang.org/cl/4080046

R=rsc
CC=golang-dev
https://golang.org/cl/4105046

R=rsc, binet
CC=golang-dev
https://golang.org/cl/3921043