runtime: fix deadlock in runtime.Stack

It shouldn't semacquire() inside an acquirem(), the runtime
thinks that means deadlock.  It actually isn't a deadlock, but it
looks like it because acquirem() does m.locks++.

Candidate for inclusion in 1.4.1.  runtime.Stack with all=true
is pretty unuseable in GOMAXPROCS>1 environment.

fixes #9321

Change-Id: Iac6b664217d24763b9878c20e49229a1ecffc805
Reviewed-on: https://go-review.googlesource.com/1600
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
reflect: remove a double negative, use the rtype.pointers method for clarity

Change-Id: Ia24e9f0da1622cededa17b2c54ff9e4bb80cf946
Reviewed-on: https://go-review.googlesource.com/1633
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
runtime: add profiling infrastructure for the Concurrent GC

Change-Id: Ia7a007444eeb1503cec27367a5c6699ce0bf4af6
Reviewed-on: https://go-review.googlesource.com/1441
Reviewed-by: Austin Clements <austin@google.com>
test: add test that gccgo failed to compile

Gccgo failed to create the type descriptor for the type used to
allocate the nil value passed to append as the second argument when
append is called with only one argument.  Calling append with only one
argument is unusual but obviously should not cause a compiler crash.

Change-Id: I530821847dfd68f0302de6ca6a84dfbc79653935
Reviewed-on: https://go-review.googlesource.com/1692
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
os: handle the sticky bit separately for *BSD and Solaris

open(2) and mkdir(2) won't set the sticky bit on *BSD and Solaris.
This behavior is mentioned on sticky(8).
see also: https://github.com/dotcloud/docker/pull/6587

Fixes #8383.

Change-Id: Ic4733700f9926b9fc2b6fd1f998acec34e518764
Reviewed-on: https://go-review.googlesource.com/1673
Reviewed-by: Ian Lance Taylor <iant@golang.org>