spec: clarify when range x does not evaluate x

Fixes issue 4644.

R=r, adonovan
CC=golang-dev
https://codereview.appspot.com/7307083
cmd/go: reject case-insensitive file name, import collisions

To make sure that Go code will work when moved to a
system with a case-insensitive file system, like OS X or Windows,
reject any package built from files with names differing
only in case, and also any package built from imported
dependencies with names differing only in case.

Fixes issue 4773.

R=golang-dev, iant
CC=golang-dev
https://codereview.appspot.com/7314104
runtime: make return from main wait for active panic

Arguably if this happens the program is buggy anyway,
but letting the panic continue looks better than interrupting it.
Otherwise things like this are possible, and confusing:

$ go run x.go
panic: $ echo $?
0
$

Fixes issue 3934.

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/7322083
runtime: show frame pointer values during throw

Should help if stack overflows start happening again.

Fixes issue 3582.

R=golang-dev, iant
CC=golang-dev
https://codereview.appspot.com/7311098
runtime: allow mem profiles with GOGC=off

Fixes issue 3586.

R=golang-dev, iant
CC=golang-dev
https://codereview.appspot.com/7304098
api: refresh next.txt

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7317049
build: clang support

This works with at least one version of clang
that existed at one moment in time.
No guarantees about clangs past or future.

To try:
        CC=clang all.bash

It does not work with the Xcode clang,
because that clang fails at printing a useful answer
to:
        clang -print-libgcc-file-name
The clang that works prints a full path name for
that command, not just "libgcc.a".

Fixes issue 4713.

R=iant, minux.ma
CC=golang-dev
https://codereview.appspot.com/7323068
os: point users of ProcessState.SysUsage to getrusage(2)

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7352044
undo CL 7310096 / 59da6744d66d

broke windows build

««« original CL description
runtime: ensure forward progress of runtime.Gosched() for locked goroutines
The removed code leads to the situation when M executes the same locked G again and again.
Fixes issue 4820.

R=golang-dev, rsc
CC=golang-dev
https://codereview.appspot.com/7310096
»»»

TBR=dvyukov
CC=golang-dev
https://codereview.appspot.com/7343050
runtime: fix unused variable warning

R=rsc, dvyukov
CC=golang-dev
https://codereview.appspot.com/7312103
net: add IPConn through Conn test

Also refactors mock ICMP stuff.

R=dave, rsc
CC=golang-dev
https://codereview.appspot.com/7325043
runtime: fix build on openbsd

R=golang-dev, jsing
CC=golang-dev
https://codereview.appspot.com/7312104

Committer: Joel Sing <jsing@google.com>
strings: better mean complexity for Count and Index.

The O(n+m) complexity is obtained probabilistically
by using Rabin-Karp algorithm, which provides the needed complexity
unless exceptional collisions occur, without memory allocation.

benchmark                 old ns/op    new ns/op    delta
BenchmarkIndexHard1         6532331      4045886  -38.06%
BenchmarkIndexHard2         8178173      4038975  -50.61%
BenchmarkIndexHard3         6973687      4042591  -42.03%
BenchmarkCountHard1         6270864      4071090  -35.08%
BenchmarkCountHard2         7838039      4072853  -48.04%
BenchmarkCountHard3         6697828      4071964  -39.20%
BenchmarkIndexTorture       2730546        28934  -98.94%
BenchmarkCountTorture       2729622        29064  -98.94%

Fixes issue 4600.

R=rsc, donovanhide, remyoudompheng
CC=golang-dev
https://codereview.appspot.com/7314095
runtime: fix sigaction struct on freebsd

Fix the sa_mask member of the sigaction struct - on FreeBSD this is
declared as a sigset_t, which is an array of four unsigned ints.
Replace the current int64 with Sigset from defs_freebsd_GOARCH, which
has the correct definition.

Unbreaks the FreeBSD builds.

R=golang-dev, dave, minux.ma
CC=golang-dev
https://codereview.appspot.com/7333047
exp/cookiejar: make cookie sorting deterministic.

Re-enable TestUpdateAndDelete, TestExpiration, TestChromiumDomain and
TestChromiumDeletion on Windows.

Sorting of cookies with same path length and same creation
time is done by an additional seqNum field.
This makes the order in which cookies are returned in Cookies
deterministic, even if the system clock is manipulated or on
systems with a low-resolution clock.

The tests now use a synthetic time: This makes cookie testing
reliable in case of bogus system clocks and speeds up the
expiration tests.

R=nigeltao, alex.brainman, dave
CC=golang-dev
https://codereview.appspot.com/7323063

Committer: Nigel Tao <nigeltao@golang.org>
misc/vim: update installation instructions to work better with some Linux distributions.

Fixes issue 3308.

R=golang-dev, minux.ma
CC=golang-dev
https://codereview.appspot.com/7301086
runtime/debug: make TestFreeOSMemory repeatable
Fixes issue 4835.

R=golang-dev, fullung
CC=golang-dev
https://codereview.appspot.com/7319050
cmd/6c, cmd/8c: cut stack frames by about half

The routine that adds an automatic to the stack was
adding ptrsize-1 to the size before rounding up.
That addition would only make sense to turn a round down
into a round up. Before a round up, it just wastes a word.

The effect was that a 6c function with one local and
one two-word function call used (8+8)+(16+8) = 40 bytes
instead of 8+16 = 24 bytes.

The wasted space mostly didn't matter, but one place where
it does matter is when trying to stay within the 128-byte
total frame constraint for #pragma textflag 7 functions.

This only affects the C compilers, not the Go compilers.

5c already had correct code, which is now copied to 6c and 8c.

R=ken2
CC=golang-dev
https://codereview.appspot.com/7303099
cmd/6c: fix build

copy+paste error while cleaning up CL 7303099 before submit

R=ken2
CC=golang-dev
https://codereview.appspot.com/7308104
runtime: preparation for non-Go threads running Go code

* Handle p==nil in signalstack by setting SS_DISABLE flag.
* Make minit only allocate a signal g if there's not one already.

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/7323072