Fix botched cgo_netbsd.go merge and remove redundant +build directive.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6282048

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6261056

Split stdout/stderr into a separate file so that can be handled
differently on some platforms. Both NetBSD and OpenBSD have defines
for stdout/stderr that require some coercion in order for cgo to
handle them correctly.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6247062

pipe2 is equivalent to pipe with flags set to 0.
However, pipe2 was only added recently. Using pipe
instead improves compatibility with NetBSD 5.

R=jsing
CC=golang-dev
https://golang.org/cl/6268045

The new BenchmarkServer avoids profiling the client code
by running it in a child process.

R=rsc
CC=golang-dev
https://golang.org/cl/6260053

Fixes #3634.

R=golang-dev, bsiegert, rsc
CC=golang-dev
https://golang.org/cl/6270047

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6273050

specifically, adds a go-test element to compilation-error-regexp-alist[-alist].
Fixes #3629.

R=golang-dev, rsc, sameer
CC=golang-dev, jba
https://golang.org/cl/6197091

The cleanup also makes it ~5% faster, but that's
not the point of this CL.

Optimizations can come in future CLs.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6286043

Removes code. No need for atoi helper.

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/6285045

R=rsc
CC=golang-dev
https://golang.org/cl/6249071

It's very unfortunate that the type of Data field of struct
RawSockaddr is [14]uint8 on Linux/ARM instead of [14]int8
on all the others.
btw, it should be [14]int8 according to my header files.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6275050

No need to fix case of "Host" string literal.

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6278049

Make it possible to run test over symlinked GOROOT.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6268046

benchmark             old ns/op    new ns/op    delta
BenchmarkFormat            2495          937  -62.44%
BenchmarkFormatNow         2308          889  -61.48%

Update #3679.

R=r
CC=golang-dev
https://golang.org/cl/6278047

Move address info flags to per-platform files. This is needed to
enable cgo on NetBSD (and later OpenBSD), as some of the currently
used AI_* defines do not exist on these platforms.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6250075

Fixes #3685.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6261053

TBR=lvd
CC=golang-dev
https://golang.org/cl/6275048

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6278045

R=rsc, ality, rogpeppe, minux.ma, dave
CC=golang-dev
https://golang.org/cl/5966075

Use perfect cuckoo hash, to avoid binary search.
Define Atom bits as offset+len in long string instead
of enumeration, to avoid string headers.

Before: 1909 string bytes + 6060 tables = 7969 total data
After: 1406 string bytes + 2048 tables = 3454 total data

benchmark          old ns/op    new ns/op    delta
BenchmarkLookup        83878        64681  -22.89%

R=nigeltao, r
CC=golang-dev
https://golang.org/cl/6262051

        16-bit uid calls are not always supported in newer kernels.

R=dave, rsc, bradfitz
CC=golang-dev
https://golang.org/cl/6279047

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6270045

        Supported in ARMv5 and above.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6284043

R=rsc
CC=golang-dev
https://golang.org/cl/6255074

Ceil  to 4.81 from 20.6 ns/op
Floor to 4.37 from 13.5 ns/op
Trunc to 3.97 from 14.3 ns/op
Also changed three MOVSDs to MOVAPDs in log_amd64.s

R=rsc, golang-dev
CC=golang-dev
https://golang.org/cl/6262048

Currently walk() doesn't check for err == SkipDir when iterating
a directory list, but such promise is made in the docs for WalkFunc.

Fixes #3486.

R=rsc, r
CC=golang-dev
https://golang.org/cl/6257059

R=dave, rsc
CC=golang-dev
https://golang.org/cl/6248070

Now that gri has made go/parser 15% faster, I offer this
change to slow back down cmd/api ~proportionately, adding
FreeBSD to the go1-checked set of platforms.

Really we should have done this earlier. This will prevent us
from breaking FreeBSD compatibility accidentally in the
future.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6279044

To avoid goroutines during init, the nextItem function was a
clever workaround. Now that init goroutines are permitted,
restore the original, simpler design.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6282043

- only compute current line position if needed
  (i.e., if a comment is present)

- added benchmark

benchmark         old ns/op    new ns/op    delta
BenchmarkParse     10902990      9313330  -14.58%

benchmark          old MB/s     new MB/s  speedup
BenchmarkParse         5.31         6.22    1.17x

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6270043

R=golang-dev, sameer, bradfitz
CC=golang-dev, jba
https://golang.org/cl/6213056

Saving the code in case we improve things enough that
it matters later, but at least right now it is not worth doing.

R=ken2
CC=golang-dev
https://golang.org/cl/6248071

Dreg from https://golang.org/cl/4629042

R=ken2
CC=golang-dev
https://golang.org/cl/6259057

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6257082

exp/html/atom benchmark:
benchmark          old ns/op    new ns/op    delta
BenchmarkLookup       199226        80770  -59.46%

exp/html benchmark:
benchmark                      old ns/op    new ns/op    delta
BenchmarkParser                  4864890      4510834   -7.28%
BenchmarkHighLevelTokenizer      2209192      1969684  -10.84%
benchmark                       old MB/s     new MB/s  speedup
BenchmarkParser                    16.07        17.33    1.08x
BenchmarkHighLevelTokenizer        35.38        39.68    1.12x

R=r
CC=golang-dev
https://golang.org/cl/6261054

The previous code was preparing arrays of entries that would be
filled if there was one entry every 128 bytes. Moving to a 4096
byte interval reduces the overhead per megabyte of address space
to 2kB from 64kB (on 64-bit systems).
The performance impact will be negative for very small MemProfileRate.

test/bench/garbage/tree2 -heapsize 800000000 (default memprofilerate)
Before: mprof 65993056 bytes (1664 bucketmem + 65991392 addrmem)
After:  mprof  1989984 bytes (1680 bucketmem +  1988304 addrmem)

R=golang-dev, rsc
CC=golang-dev, remy
https://golang.org/cl/6257069

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6244071

The previous heap profile format did not include buckets with
zero used bytes. Also add several missing MemStats fields in
debug mode.

R=golang-dev, rsc
CC=golang-dev, remy
https://golang.org/cl/6249068

50% fewer mallocs in HTML tokenization, resulting in 25% fewer mallocs
in parsing go1.html.

Making the parser use integer comparisons instead of string comparisons
will be a follow-up CL, to be co-ordinated with Andy Balholm's work.

exp/html benchmarks before/after:

BenchmarkParser	     500	   4754294 ns/op	  16.44 MB/s
        parse_test.go:409: 500 iterations, 14651 mallocs per iteration
BenchmarkRawLevelTokenizer	    2000	    903481 ns/op	  86.51 MB/s
        token_test.go:678: 2000 iterations, 28 mallocs per iteration
BenchmarkLowLevelTokenizer	    2000	   1260485 ns/op	  62.01 MB/s
        token_test.go:678: 2000 iterations, 41 mallocs per iteration
BenchmarkHighLevelTokenizer	    1000	   2165964 ns/op	  36.09 MB/s
        token_test.go:678: 1000 iterations, 6616 mallocs per iteration

BenchmarkParser	     500	   4664912 ns/op	  16.76 MB/s
        parse_test.go:409: 500 iterations, 11266 mallocs per iteration
BenchmarkRawLevelTokenizer	    2000	    903065 ns/op	  86.55 MB/s
        token_test.go:678: 2000 iterations, 28 mallocs per iteration
BenchmarkLowLevelTokenizer	    2000	   1260032 ns/op	  62.03 MB/s
        token_test.go:678: 2000 iterations, 41 mallocs per iteration
BenchmarkHighLevelTokenizer	    1000	   2143356 ns/op	  36.47 MB/s
        token_test.go:678: 1000 iterations, 3231 mallocs per iteration

R=r, rsc, rogpeppe
CC=andybalholm, golang-dev
https://golang.org/cl/6255062