sort: simplify rotate and reduce calls to it

Move the checks for empty rotate changes
from the beginning of rotate to the callers.

Remove additional variable p used instead of existing m with same value.

Remove special casing of equal ranges (i==j) to exit early as no
work is saved vs checking (i!=j) and  making a single
swapRange call if this is false.

benchmark                   old ns/op      new ns/op      delta
BenchmarkStableString1K     417195         425218         +1.92%
BenchmarkStableInt1K        126661         124498         -1.71%
BenchmarkStableInt64K       10365014       10417438       +0.51%
BenchmarkStable1e2          132151         130648         -1.14%
BenchmarkStable1e4          42027428       40812649       -2.89%
BenchmarkStable1e6          8524772364     8430192391     -1.11%

Change-Id: Ia7642e9d31408496970c700f5843d53cc3ebe817
Reviewed-on: https://go-review.googlesource.com/2100
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
test/fixedbugs/issue9355: fix build on arm and power64

Change-Id: I1ef770184ad1d42bcb58714d559f2cc866a919ab
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/1880
Reviewed-by: Keith Randall <khr@golang.org>
misc/cgo/test: get rid of the backdoor package

For Go 1.5, we can use go:linkname rather than assembly thunk for gc.
Gccgo already has support for //extern.

Change-Id: I5505aa247dd5b555112f7261ed2f192c81cf0bdf
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/1888
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
database/sql: Remove unnecessary call to maybeOpenNewConnections

numCanOpen will never be larger than 0 in maybeOpenNewConnections() when this
code path is taken, so no new connections can ever be opened.

Change-Id: Id1302e8d9afb3a67be61b5e738fe07ef81d20fe0
Reviewed-on: https://go-review.googlesource.com/1550
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
reflect: fix func layout test for nacl build

This test code is ugly.  There must be a better way.
But for now, fix the build.

Change-Id: I33064145ea37f11abf040ec97caa87669be1a9fa
Reviewed-on: https://go-review.googlesource.com/2114
Reviewed-by: Ian Lance Taylor <iant@golang.org>
regexp: fix typo in comment: s/onpass/onepass/

Change-Id: Idff57050a34d09e7fa9b77e9b53d61bb5ea2a71c
Reviewed-on: https://go-review.googlesource.com/2095
Reviewed-by: Minux Ma <minux@golang.org>