runtime: no escape for some functions on AIX

Reviewed-on: https://go-review.googlesource.com/88236

From-SVN: r256874

gcc/go/gofrontend/MERGE

@@ -1,4 +1,4 @@
-cf33aedb66b5121708f5640443c1336080a47fe5
+8195b62d353026256037fa44409c4ad95762e6b7
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/go/runtime/netpoll_aix.go

@@ -34,12 +34,15 @@ const _PS_DELETE = 0x2
 //extern pollset_create
 func pollset_create(maxfd int32) pollset_t
 
+//go:noescape
 //extern pollset_ctl
 func pollset_ctl(ps pollset_t, pollctl_array *poll_ctl, array_length int32) int32
 
+//go:noescape
 //extern pollset_poll
 func pollset_poll(ps pollset_t, polldata_array *pollfd, array_length int32, timeout int32) int32
 
+//go:noescape
 //extern pipe
 func libc_pipe(fd *int32) int32
 

libgo/go/runtime/stubs2.go

@@ -10,6 +10,7 @@ package runtime
 
 import "unsafe"
 
+//go:noescape
 func read(fd int32, p unsafe.Pointer, n int32) int32
 func closefd(fd int32) int32