go/parser: ParseExpr must accept type expressions

My old code was trying to be too smart.
Also: Slightly better error message format
for gofmt -r pattern errors.

Fixes issue 4406.

R=golang-dev, adg
CC=golang-dev
https://codereview.appspot.com/8267045
bytes: don't leave mprotect-ed pages after unsafe test.

Fixes inscrutable GC faults during testing.

R=golang-dev, bradfitz, dave, fullung
CC=golang-dev
https://codereview.appspot.com/8300044

Committer: Brad Fitzpatrick <bradfitz@golang.org>
net/http: don't allocate 0-byte io.LimitedReaders for GET requests

Save an allocation per GET request and don't call io.LimitedReader(r, 0)
just to read 0 bytes.  There's already an eofReader global variable
for when we just want a non-nil io.Reader to immediately EOF.

(Sorry, I know Rob told me to stop, but I was bored on the plane and
wrote this before I received the recent "please, really stop" email.)

benchmark                         old ns/op    new ns/op    delta
BenchmarkServerHandlerTypeLen         13888        13279   -4.39%
BenchmarkServerHandlerNoLen           12912        12229   -5.29%
BenchmarkServerHandlerNoType          13348        12632   -5.36%
BenchmarkServerHandlerNoHeader        10911        10261   -5.96%

benchmark                        old allocs   new allocs    delta
BenchmarkServerHandlerTypeLen            20           19   -5.00%
BenchmarkServerHandlerNoLen              18           17   -5.56%
BenchmarkServerHandlerNoType             18           17   -5.56%
BenchmarkServerHandlerNoHeader           13           12   -7.69%

benchmark                         old bytes    new bytes    delta
BenchmarkServerHandlerTypeLen          1913         1878   -1.83%
BenchmarkServerHandlerNoLen            1878         1843   -1.86%
BenchmarkServerHandlerNoType           1878         1844   -1.81%
BenchmarkServerHandlerNoHeader         1085         1051   -3.13%

Fixes Issue 5188

R=golang-dev, adg, r
CC=golang-dev
https://codereview.appspot.com/8297044
bufio: make it a little clearer how the default Scanner splits lines.
Just commentary, no semantic change.

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/8329043
doc/go1.1.html: state that the heap is bigger on 64-bit machines
Be deliberately vague, since the precise details should not be depended upon.
Fixes issue 5155.

R=golang-dev, gri, adg
CC=golang-dev
https://codereview.appspot.com/8283044
api: update next.txt.

Update Issue 4871

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/8287044
net/smtp: allow PLAIN auth when advertised

The smtp package originally allowed PLAIN whenever, but then
the TLS check was added for paranoia, but it's too paranoid:
it prevents using PLAIN auth even from localhost to localhost
when the server advertises PLAIN support.

This CL also permits the client to send PLAIN if the server
advertises it.

Fixes Issue 5184

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/8279043
doc/go1.1.html: document os/signal.Stop
Also fix the sort order of the laundry list.

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/8325044
C: add James Tucker (Google CLA)

R=golang-dev, gri
CC=golang-dev
https://codereview.appspot.com/8253044
database/sql: improve standard deviation response time under high concurrency

See https://github.com/raggi/go-and-java for runtime benchmark.

The patch reduces the amount of map key search, moving connection oriented
variables onto the connection structs.

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/8092045

Committer: Brad Fitzpatrick <bradfitz@golang.org>
math/big: minor cleanups

- comment fixes
- s/z/x/ in (*rat).Float64 to match convention for functions
  returning a non-*Rat
- minor test output tweaking

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/8327044
doc/go1.1.html: document the state of gccgo
Fixes issue 5053.

R=adg, iant
CC=golang-dev
https://codereview.appspot.com/8337043
doc: link the race detector document into the release notes
Also:
- put GORACE into the go env command
- do minor housekeeping on the race detector article

Fixes issue 4995.

R=golang-dev, adg
CC=golang-dev
https://codereview.appspot.com/8319044
misc/dist: include race detector packages in binary distributions

Fixes issue 4596.

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/8327045
doc: simplify How to write Go code article

This version just tells you what to do, rather
than trying to teach you how it all works.
Should be much better for newcomers.

R=dave, gary.burd, alcosholik, r
CC=golang-dev
https://codereview.appspot.com/8247044
doc: mention godoc.org in "How to Write Go Code"

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/8344043
runtime: fix data/bss shadow memory mapping for race detector
Fixes issue 5175.
Race detector runtime expects values passed to MapShadow() to be page-aligned,
because they are used in mmap() call. If they are not aligned mmap() trims
either beginning or end of the mapping.

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/8325043

Committer: Andrew Gerrand <adg@golang.org>
A+C: added Alexei Sholik (individual CLA)

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/8351043
doc: fix typos and trailing spaces

R=golang-dev, adg
CC=golang-dev
https://codereview.appspot.com/8285044

Committer: Robert Griesemer <gri@golang.org>
doc: fix typos in go1.1

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/8342044