go/parser: Use test-specific filesets to avoid races.

Only affects test code.

Fixes issue 9025.
Fixes issue 9130.

LGTM=r, adonovan
R=adonovan, r
CC=golang-codereviews
https://codereview.appspot.com/180920043
cmd/go: fix running pprof on windows.

Fixes issue 9149.

LGTM=alex.brainman, rsc
R=rsc, dave, alex.brainman
CC=golang-codereviews
https://codereview.appspot.com/176170043

Committer: Russ Cox <rsc@golang.org>
image/jpeg: handle Read returning n > 0, err != nil in d.fill

Fixes issue 9127.

LGTM=r
R=bradfitz, r
CC=golang-codereviews, nigeltao
https://codereview.appspot.com/178120043
[dev.cc] all: merge default (95f5614b4648) into dev.cc

TBR=austin
CC=golang-codereviews
https://codereview.appspot.com/177220044
[dev.cc] runtime: convert dragonfly/386 port to Go

LGTM=rsc
R=rsc, bradfitz
CC=golang-codereviews
https://codereview.appspot.com/178210043
[dev.cc] 9g: fill progtable for CC, V, and VCC instruction variants

This adds some utilities for converting between the CC, V, and
VCC variants of operations and uses these to derive the
ProgInfo entries for these variants (which are identical to
the ProgInfo for the base operations).

The 9g peephole optimizer will also use these conversion
utilities.

LGTM=minux, rsc
R=rsc, dave, minux
CC=golang-codereviews
https://codereview.appspot.com/180110044
[dev.cc] 9g: peephole optimizer

This was based on the 9c peephole optimizer, modified to work
with code generated by gc and use the proginfo infrastructure
in gc.

LGTM=rsc
R=rsc, bradfitz, minux
CC=golang-codereviews
https://codereview.appspot.com/179190043
[dev.cc] cmd/5g,cmd/6g,cmd/9g: fix warnings on Plan 9

warning: src/cmd/5g/reg.c:461 format mismatch d VLONG, arg 5
warning: src/cmd/6g/reg.c:396 format mismatch d VLONG, arg 5
warning: src/cmd/9g/reg.c:440 format mismatch d VLONG, arg 5

LGTM=minux
R=rsc, minux
CC=golang-codereviews
https://codereview.appspot.com/179300043
[dev.cc] 9l: make R_CALLPOWER like ELF's R_PPC64_REL24

These accomplished the same thing, but R_CALLPOWER expected
the whole instruction to be in the addend (and completely
overwrote what was in the text section), while R_PPC64_REL24
overwrites only bits 6 through 24 of whatever was in the text
section.  Make R_CALLPOWER work like R_PPC64_REL24 to ease the
implementation of dynamic linking.

LGTM=rsc
R=rsc
CC=golang-codereviews, minux
https://codereview.appspot.com/177430043