[dev.cc] all: merge dev.power64 (7667e41f3ced) into dev.cc

This is to reduce the delta between dev.cc and dev.garbage to just garbage collector changes.

These are the files that had merge conflicts and have been edited by hand:
        malloc.go
        mem_linux.go
        mgc.go
        os1_linux.go
        proc1.go
        panic1.go
        runtime1.go

LGTM=austin
R=austin
CC=golang-codereviews
https://codereview.appspot.com/174180043

1 files changed, 2 insertions, 4 deletions

diff --git a/src/runtime/mgc0.go b/src/runtime/mgc0.go
index 3a7204b54..6d4ae61c1 100644
--- a/src/runtime/mgc0.go
+++ b/src/runtime/mgc0.go
@@ -28,7 +28,7 @@ func gc_unixnanotime(now *int64) {
 
 func freeOSMemory() {
 	gogc(2) // force GC and do eager sweep
-	onM(scavenge_m)
+	systemstack(scavenge_m)
 }
 
 var poolcleanup func()
@@ -60,10 +60,8 @@ func clearpools() {
 	}
 }
 
-func gosweepone() uintptr
-func gosweepdone() bool
-
 func bgsweep() {
+	sweep.g = getg()
 	getg().issystem = true
 	for {
 		for gosweepone() != ^uintptr(0) {