Thanks to Minux and Remy for their advice.

The EOR optimisation is applied to a few places in the stdlib.

// hash/crc32/crc32.go
func update(crc uint32, tab *Table, p []byte) uint32 {
	crc = ^crc
	for _, v := range p {
        	crc = tab[byte(crc)^v] ^ (crc >> 8)
	}
	return ^crc
}

before:

--- prog list "update" ---
0164 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:101) TEXT        update+0(SB),$12-24
0165 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:101) MOVW        tab+4(FP),R8
0166 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:102) MOVW        crc+0(FP),R0
0167 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:102) EOR         $-1,R0,R5
0168 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:103) MOVW        p+8(FP),R0
0169 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:103) MOVW        R0,autotmp_0019+-12(SP)

after:

--- prog list "update" ---
0164 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:101) TEXT        update+0(SB),$12-24
0165 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:101) MOVW        tab+4(FP),R8
0166 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:102) MOVW        crc+0(FP),R0
0167 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:102) MVN         R0,R5
0168 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:103) MOVW        p+8(FP),R0
0169 (/home/dfc/go/src/pkg/hash/crc32/crc32.go:103) MOVW        R0,autotmp_0019+-12(SP)

After 5l has done its work,

        crc = ^crc
   3d710:       e59d0014        ldr     r0, [sp, #20]
   3d714:       e3e0b000        mvn     fp, #0
   3d718:       e020500b        eor     r5, r0, fp

becomes

        crc = ^crc
   3d710:       e59d0014        ldr     r0, [sp, #20]
   3d714:       e1e05000        mvn     r5, r0

The MOVB optimisation has a small impact on the stdlib, in strconv
and gzip.

// GZIP (RFC 1952) is little-endian, unlike ZLIB (RFC 1950).
func put2(p []byte, v uint16) {
        p[0] = uint8(v >> 0)
        p[1] = uint8(v >> 8)
}

before:

--- prog list "put2" ---
1369 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:76) TEXT       put2+0(SB),$0-16
1370 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:76) MOVHU      v+12(FP),R4
1371 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVHU      R4,R0
1372 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVHU      R0,R0
1373 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVBU      R0,R1
1374 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVBU      R1,R3
1375 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVW       $p+0(FP),R1

after:

--- prog list "put2" ---
1369 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:76) TEXT       put2+0(SB),$0-16
1370 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:76) MOVHU      v+12(FP),R4
1371 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVHU      R4,R0
1372 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVBU      R0,R1
1373 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVBU      R1,R3
1374 (/home/dfc/go/src/pkg/compress/gzip/gzip.go:77) MOVW       $p+0(FP),R1

R=remyoudompheng, rsc, minux.ma
CC=golang-dev
https://golang.org/cl/6674048

Fixes #4282.

R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6759052

Fixes #4275.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6759053

Used to print:
../test/torture.go:116: internal compiler error: bad width: 0463 (../test/torture.go:116) MOVB    ,BX (0, 8)

R=nigeltao, rsc
CC=golang-dev
https://golang.org/cl/6736068

- Allow secondary values below the default value in second form. This is
  to support before tags for secondary values, as used by Chinese.
- Eliminate collation elements that are guaranteed to be immaterial
  after a weight increment.

R=r
CC=golang-dev
https://golang.org/cl/6739051

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6763043

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6743059

different indexes for values and index blocks. Fixes many regressions.

R=r
CC=golang-dev
https://golang.org/cl/6737057

R=r
CC=golang-dev
https://golang.org/cl/6752043

R=r
CC=golang-dev
https://golang.org/cl/6749058

Also defend our symbol prefixes (now just "go" and "type")
from use as import paths.

Fixes #4257.

R=ken2
CC=golang-dev
https://golang.org/cl/6744072

R=dvyukov
CC=golang-dev
https://golang.org/cl/6733058

Also:
- type-checking receivers
- get rid of some multiple errors at the same position

R=rsc, minux.ma
CC=golang-dev
https://golang.org/cl/6709061

Fixes #4097.

R=rsc
CC=golang-dev, gri
https://golang.org/cl/6749059

R=golang-dev, rsc
CC=0xe2.0x9a.0x9b, golang-dev
https://golang.org/cl/6742063

includes step 0: synthesize outparams, from 6600044
step 1: give outparams loopdepth 0 and verify unchanged results
step 2: generate esc:$mask tags, but still tie to sink if a param has mask != 0
next step: use in esccall (and ORETURN with implicit OAS2FUNC) to avoid tying to sink

R=rsc
CC=golang-dev
https://golang.org/cl/6610054

cmd/gc: track parameter flow, step 0: synthesize name nodes for anonymous PPARAMOUTs without breaking anything.

further work on parameter flow tracking for escape analysis depends on this.

R=rsc
CC=golang-dev
https://golang.org/cl/6600044

in typecheck and walk, conversion from OAS2RECV to OAS2
and to OSELRECV2 duplicated the ->rlist->n to ->right
thereby destroying the strict tree-ness of the AST (up to
ONAMES) of course.  Several recursions in esc.c and inl.c
and probably elsewhere assume nodes of the tree aren't duplicated.
rather than defensively code around this, i'd rather assert
these cases away and fix their cause.

(this was tripped in 6741044)

R=rsc
CC=golang-dev
https://golang.org/cl/6750043

It's common to use the go list command in shell scripts, but
currently it's awkward to print a string slice from the Package
type in a way that's easily parseable by the shell.  For example:

        go list -f '{{range .Deps}}{{.}}
        {{end}}'

(and even that prints an unwanted new line at the end|).

To make this easier, this CL adds a "join" function to the
format template.

        go list -f '{{join .Deps "\n"}}'

R=rsc, dsymonds, minux.ma, remyoudompheng, r
CC=golang-dev
https://golang.org/cl/6680044

Fixes #4230.

R=golang-dev, rsc
CC=golang-dev, remy
https://golang.org/cl/6640056

R=rsc, dave
CC=golang-dev
https://golang.org/cl/6638043

R=dsymonds
CC=golang-dev
https://golang.org/cl/6736057

Previously, multi-byte characters were not allowed. Also certain single-byte
characters, such as '-', were disallowed.
Fixes #3813.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6641052

R=golang-dev, minux.ma, dave, rsc
CC=golang-dev
https://golang.org/cl/6643046

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6749055

R=rsc, pkleiweg
CC=golang-dev
https://golang.org/cl/6725052

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6734055

R=rsc
CC=golang-dev
https://golang.org/cl/6569057

I just realized that there is no good place for adding
exposed function or method tests because server, unicast
and multicast_test.go do test complicated multiple test
objects, platform behaviros, protocol behaviors and API,
at the same time. Perhaps splitting them into per test
object might be better, so this CL provides tests focused
on API.

R=rsc
CC=gobot, golang-dev
https://golang.org/cl/6501057

Was not in sync with runtime.go, but the diffs
didn't really matter, so nothing broke.

R=ken2
CC=golang-dev
https://golang.org/cl/6733057

R=golang-dev, minux.ma, ality
CC=golang-dev
https://golang.org/cl/6743052

Fixes #3284.

R=golang-dev, r, rsc
CC=golang-dev
https://golang.org/cl/6643043

Fixes #3783.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6737053

Someone new to the language may not know the connection between ints and arrays, which was the only thing that the previous error told you anything about.

Fixes #4256.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6739048

   PauseNs is a circular buffer of recent pause times, and the
most recent one is at [((NumGC-1)+256)%256].

   Also fix comments cross-linking the Go and C definition of
various structs.

R=golang-dev, rsc, bradfitz
CC=golang-dev
https://golang.org/cl/6657047

R=bradfitz
CC=golang-dev
https://golang.org/cl/6713043

R=golang-dev, bradfitz, dave
CC=golang-dev
https://golang.org/cl/6733047

also add a cleanup phase to cmd/go/test.bash.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6741050

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6742053

benchmark                      old ns/op    new ns/op    delta
BenchmarkUint32Div7                  281           75  -73.06%
BenchmarkUint32Div37                 281           75  -73.02%
BenchmarkUint32Div123                281           75  -73.02%
BenchmarkUint32Div763                280           75  -72.89%
BenchmarkUint32Div1247               280           75  -72.93%
BenchmarkUint32Div9305               281           75  -73.02%
BenchmarkUint32Div13307              281           75  -73.06%
BenchmarkUint32Div52513              281           75  -72.99%
BenchmarkUint32Div60978747           281           63  -77.33%
BenchmarkUint32Div106956295          280           63  -77.21%
BenchmarkUint32Mod7                  280           77  -72.21%
BenchmarkUint32Mod37                 280           77  -72.18%
BenchmarkUint32Mod123                280           77  -72.25%
BenchmarkUint32Mod763                280           77  -72.18%
BenchmarkUint32Mod1247               280           77  -72.21%
BenchmarkUint32Mod9305               280           77  -72.21%
BenchmarkUint32Mod13307              280           77  -72.25%
BenchmarkUint32Mod52513              280           77  -72.18%
BenchmarkUint32Mod60978747           280           63  -77.25%
BenchmarkUint32Mod106956295          280           63  -77.21%

R=dave, rsc
CC=dave, golang-dev, rsc
https://golang.org/cl/6717043