[release-branch.go1.9] all: merge master into release-branch.go1.9

57912032 runtime: mapassign_* should use typedmemmove to update keys
38052559 all: remove some manual hyphenation
f096b5b3 runtime: mark activeModules nosplit/nowritebarrier
3e3da546 math/bits: fix example for OnesCount64
9b1e7cf2 math/bits: add examples for OnesCount functions
b01db023 misc/cgo/testsanitizers: also skip tsan11/tsan12 when using GCC
a279b53a reflect: document how DeepEqual handles cycles
909f409a doc: mention handling of moved GOROOT in 1.9 release notes
58ad0176 doc: use better wording to explain type-aware completion
92dac21d doc: replace paid with commercial
9bb98e02 doc/1.9: add CL 43712, ReverseProxy of HTTP/2 trailers to the release notes.
78d74fc2 doc: clarify that Gogland is for paid IntelliJ platform IDEs
54950472 doc/1.9: fix broken html link in CL 53030/53210
890e0e86 doc: fix bad link in go1.9 release notes
be596f04 doc/1.9: fix stray html in CL 53030
0173631d encoding/binary: add examples for varint functions
ac0ccf3c doc/1.9: add CL 36696 for crypto/x509 to the release notes
cc402c2c doc: hide blog content for golang.google.cn
f396fa42 internal/poll: don't add non-sockets to runtime poller
664cd26c cmd/vet: don't exit with failure on type checking error
a8730cd9 doc: hide video and share if being served from CN
b63db76c testsanitizers: check that tsan program runs, skip tsan10 on gcc
193eda72 time: skip ZoneAbbr test in timezones with no abbreviation
6f08c935 cmd/go: show examples with empty output in go test -list
f20944de cmd/compile: set/unset base register for better assembly print
623e2c46 runtime: map bitmap and spans during heap initialization
780249ee runtime: fall back to small mmaps if we fail to grow reservation
31b2c4cc .github: add .md extension to SUPPORT file
ac29f30d plugin: mention that there are known bugs with plugins
45a4609c cmd/dist: skip moved GOROOT on Go's Windows builders when not sharding tests
e157fac0 test: add README
835dfef9 runtime/pprof: prevent a deadlock that SIGPROF might create on mips{,le}
df91b804 doc: list editor options by name, not plugin name
3d9475c0 doc: cleanup editor page
b9661a14 doc: add Atom to editor guide
ee392ac1 cmd/compile: consider exported flag in namedata

Change-Id: I3a48493e8c05d97cb3b61635503ef0ccd646e5cb