cmd/link/internal/ld: Skip combining dwarf for darwin/arm.

Change-Id: I3a6df0a76d57db7cb6910f4179a6ce380f219a37
Reviewed-on: https://go-review.googlesource.com/10442Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/link/internal/ld/lib.go

@@ -1055,6 +1055,8 @@ func hostlink() {
 	}
 
 	if Debug['s'] == 0 && debug_s == 0 && HEADTYPE == obj.Hdarwin {
+		// Skip combining dwarf on arm.
+		if Thearch.Thechar != '5' && Thearch.Thechar != '7' {
 			dsym := fmt.Sprintf("%s/go.dwarf", tmpdir)
 			if out, err := exec.Command("dsymutil", "-f", outfile, "-o", dsym).CombinedOutput(); err != nil {
 				Ctxt.Cursym = nil
@@ -1072,6 +1074,7 @@ func hostlink() {
 				Exitf("%s: rename(%s, %s) failed: %v", os.Args[0], combinedOutput, outfile, err)
 			}
 		}
+	}
 }
 
 func ldobj(f *obj.Biobuf, pkg string, length int64, pn string, file string, whence int) {