runtime: precise garbage collection of hashmaps

R=golang-dev, rsc
CC=dave, dvyukov, golang-dev, minux.ma, remyoudompheng
https://codereview.appspot.com/7252047

Committer: Russ Cox <rsc@golang.org>
cmd/go: indicate that flags unrecognized by 'go test' must follow package specification

R=rsc, minux.ma
CC=golang-dev
https://codereview.appspot.com/7300063

Committer: Russ Cox <rsc@golang.org>
net: fix unixgram

The socket for AF_UNIX domain with SOCK_DGARM type isn't
allowed to work with syscall listen.

R=rsc
CC=golang-dev
https://codereview.appspot.com/7310068
log/syslog: remove socket files after tests

R=golang-dev, iant
CC=golang-dev
https://codereview.appspot.com/7305065
bytes: annotate assembly functions with //go:noescape

R=golang-dev, agl, bradfitz, rsc
CC=golang-dev
https://codereview.appspot.com/7299064
crypto/x509: allow MS/NS SCG key usage as ServerAuth.

By default, crypto/x509 assumes that users wish to validate
certificates for ServerAuth. However, due to historical reasons,
COMODO's intermediates don't specify ServerAuth as an allowed key
usage.

Rather NSS and CryptoAPI both allow these SGC OIDs to be equivalent to
ServerAuth.

R=rsc
CC=golang-dev
https://codereview.appspot.com/7312070
testing: be explicit about use of b.N

R=golang-dev, minux.ma
CC=golang-dev
https://codereview.appspot.com/7314071
crypto/x509: disable SCG test with system validation.

On Windows, CryptoAPI is finding an alternative validation path. Since
this is a little non-deterministic, this change disables that test
when using system validation.

R=golang-dev
CC=golang-dev
https://codereview.appspot.com/7313068
spec: clarify that f(g()) requires that g return >= 1 value

Fixes issue 4573.

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7322043