cmd/objdump: skip fork test on darwin/arm

Change-Id: I1d1eb71014381452d1ef368431cb2556245a35ab
Reviewed-on: https://go-review.googlesource.com/6250Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>

src/cmd/objdump/objdump_test.go

@@ -18,6 +18,10 @@ func buildObjdump(t *testing.T) (tmp, exe string) {
 	switch runtime.GOOS {
 	case "android", "nacl":
 		t.Skipf("skipping on %s", runtime.GOOS)
+	case "darwin":
+		if runtime.GOARCH == "arm" {
+			t.Skipf("skipping on %s/%s", runtime.GOOS, runtime.GOARCH)
+		}
 	}
 
 	tmp, err := ioutil.TempDir("", "TestObjDump")