cmd/internal/gc: fix build on big endian systems

The siz argument to both runtime.newproc and runtime.deferproc is
int32, not uintptr. This problem won't manifest on little-endian
systems because that stack slot is uintptr sized anyway. However,
on big-endian systems, it will make a difference.

Change-Id: I2351d1ec81839abe25375cff95e327b80764c2b5
Reviewed-on: https://go-review.googlesource.com/9647
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/cmd/internal/gc/cgen.go

@@ -2396,7 +2396,7 @@ func Ginscall(f *Node, proc int) {
 		if HasLinkRegister() {
 			stk.Xoffset += int64(Ctxt.Arch.Ptrsize)
 		}
-		Thearch.Ginscon(Thearch.Optoas(OAS, Types[Tptr]), int64(Argsize(f.Type)), &stk)
+		Thearch.Ginscon(Thearch.Optoas(OAS, Types[TINT32]), int64(Argsize(f.Type)), &stk)
 
 		// FuncVal* at 8(SP)
 		stk.Xoffset = int64(Widthptr)