runtime.newproc/ready are deliberately sloppy about waking new M's,
they only ensure that there is at least 1 spinning M.
Currently to compensate for that, schedule() checks if the current P
has local work and there are no spinning M's, it wakes up another one.
It does not work if goroutines do not call schedule.
With this change a spinning M wakes up another M when it finds work to do.
It's also not ideal, but it fixes the underutilization.
A proper check would require to know the exact number of runnable G's,
but it's too expensive to maintain.
Fixes #5586.
This is reincarnation of cl/9776044 with the bug fixed.
The bug was due to code added after cl/9776044 was created:
if(tick - (((uint64)tick*0x4325c53fu)>>36)*61 == 0 && runtime·sched.runqsize > 0) {
        runtime·lock(&runtime·sched);
        gp = globrunqget(m->p, 1);
        runtime·unlock(&runtime·sched);
}
If M gets gp from global runq here, it does not reset m->spinning.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/10743044

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/10855043

Currently it crashes as follows:
fatal error: unknown pc
...
goroutine 71698 [runnable]:
runtime.racegoend()
        src/pkg/runtime/race.c:171
runtime.goexit()
        src/pkg/runtime/proc.c:1276 +0x9
created by runtime_test.testConcurrentReadsAfterGrowth
        src/pkg/runtime/map_test.go:264 +0x332

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/10674047

R=r
CC=andybons, golang-dev
https://golang.org/cl/11148043

If you compute the size by subtraction from the address
of the next symbol, it helps to wait until the symbols have
been sorted by address.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/11143043

R=r, andybons
CC=andybons, golang-dev
https://golang.org/cl/10977043

R=khr
CC=golang-dev
https://golang.org/cl/11131043

Instead, rely on the type checker.

R=adonovan
CC=golang-dev
https://golang.org/cl/10826044

R=golang-dev, dsymonds, bradfitz
CC=golang-dev
https://golang.org/cl/11095043

Fixes #5783

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/10956043

The notion of a named type is crucial for the definition
of type identity, assignability, definitions of methods.
Explicitly introduce the notion with an extra sentence.

Fixes #5682.

R=r, rsc, iant
CC=golang-dev
https://golang.org/cl/11055043

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/11080043

Fixes #5843.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/11073043

Merging a couple of CLs into one, since they collided in my client
and I'm lazy.

1) Fix up output in "go test -cover" case.
We need to tell the testing package the name of the package being tested
and the name of the package being covered. It can then sort out the report.

2) Filter out the _test.go files from coverage processing. We want to measure
what the tests cover, not what's covered in the tests,
The coverage for encoding/gob goes from 82.2% to 88.4%.
There may be a cleaner way to do this - suggestions welcome - but ça suffit.

Fixes #5810.

R=rsc
CC=golang-dev
https://golang.org/cl/10868047

Fixes #5787.

R=r
CC=golang-dev
https://golang.org/cl/11057043

R=r, rsc, andybons
CC=andybons, golang-dev
https://golang.org/cl/10890045

Fix warning found by clang 3.3.

R=rsc, r
CC=golang-dev
https://golang.org/cl/11022043

R=r
CC=golang-dev
https://golang.org/cl/10758044

Fixes #5503.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/10989043

CL 10869046 changed cmd/go to checkout master branch, so
for "go get -u" to work, it must "git pull" instead of
"git fetch". Added "--ff-only" so that it won't accidentally
overwrite user changes.

R=dsymonds
CC=golang-dev
https://golang.org/cl/10907043

Fixes #5809.

R=golang-dev, dave, rsc, nigeltao
CC=golang-dev
https://golang.org/cl/10785043

R=golang-dev, dave, adg
CC=golang-dev
https://golang.org/cl/10862045

Part 3 of several.

* Linux has grown a SetsockoptByte.
* SetsockoptIPMreqn is handled directly by syscall_linux.go and syscall_freebsd.go.

R=golang-dev, mikioh.mikioh, r, bradfitz
CC=golang-dev
https://golang.org/cl/10775043

Generated by addca.

R=gobot
CC=golang-dev
https://golang.org/cl/10868046

The lzw.NewReader doc comment says, "It is the caller's responsibility
to call Close on the ReadCloser when finished reading."

Thanks to Andrew Bonventre for noticing this.

R=r, dsymonds, adg
CC=andybons, golang-dev
https://golang.org/cl/10821043

R=dsymonds
CC=golang-dev
https://golang.org/cl/10933044

Instead, leave the error testing to the type checker, eventually.

Fixes #5827.

R=adonovan
CC=golang-dev
https://golang.org/cl/10917043

ReadMIMEHeader is used by net/http, net/mail, and
mime/multipart.

Don't do so many small allocations. Calculate up front
how much we'll probably need.

benchmark                  old ns/op    new ns/op    delta
BenchmarkReadMIMEHeader         8433         7467  -11.45%

benchmark                 old allocs   new allocs    delta
BenchmarkReadMIMEHeader           23           14  -39.13%

benchmark                  old bytes    new bytes    delta
BenchmarkReadMIMEHeader         1705         1343  -21.23%

R=golang-dev, r, iant, adg
CC=golang-dev
https://golang.org/cl/8179043

Generated by addca.

R=gobot
CC=golang-dev
https://golang.org/cl/10840044

origin/master is always a remote branch, and it doesn't make sense to
switch to a remote branch. master is the default branch that tracks it.

R=adg
CC=golang-dev, matt.jibson
https://golang.org/cl/10869046

R=golang-dev, dave
CC=golang-dev
https://golang.org/cl/10761048

Fixes #5760.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/10871043

This does not include AES-GCM yet. Also, it assumes that the handshake and
certificate signature hash are always SHA-256, which is true of the ciphersuites
that we currently support.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/10762044

R=gri, r
CC=golang-dev
https://golang.org/cl/10679047

using m->tls[0] to save ucontext pointer is not re-entry safe, and
the old code didn't set it before the early return when signal is
received on non-Go threads.

so misc/cgo/test used to hang when testing issue 5337.

R=golang-dev, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/10076045

Escape analysis needs the right curfn value on a dclfunc node, otherwise it will not analyze the function.
When generating method value wrappers, we forgot to set the curfn correctly.

Fixes #5753.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/10383048

A struct with a single field was considered as equivalent to the
field type, which is incorrect is the field is blank.

Fields with padding could make the compiler think some
types are comparable when they are not.

Fixes #5698.

R=rsc, golang-dev, daniel.morsing, bradfitz, gri, r
CC=golang-dev
https://golang.org/cl/10271046

R=golang-dev, dsymonds, dominik.honnef
CC=golang-dev
https://golang.org/cl/9293043

TBR=golang-dev
CC=golang-dev
https://golang.org/cl/10856043

When deleting a timer, a panic due to nil deref
would leave a lock held, possibly leading to a deadlock
in a defer. Instead return false on a nil timer.

Fixes #5745.

R=golang-dev, daniel.morsing, dvyukov, rsc, iant
CC=golang-dev
https://golang.org/cl/10373047