[dev.ssa] cmd/compile: treat unsafe.Pointer as a pointer

Change-Id: I3f3ac3055c93858894b8852603d79592bbc1696b
Reviewed-on: https://go-review.googlesource.com/12140Reviewed-by: Keith Randall <khr@golang.org>

src/cmd/compile/internal/gc/type.go

@@ -56,7 +56,7 @@ func (t *Type) IsFloat() bool {
 }
 
 func (t *Type) IsPtr() bool {
-	return t.Etype == TPTR32 || t.Etype == TPTR64 ||
+	return t.Etype == TPTR32 || t.Etype == TPTR64 || t.Etype == TUNSAFEPTR ||
 		t.Etype == TMAP || t.Etype == TCHAN || t.Etype == TFUNC
 }