cmd/internal/obj/x86: skip test when GOHOSTARCH is set

It's causing the darwin-386 builder to fail with:

--- FAIL: TestDynlink (0.07s)
    obj6_test.go:118: error exit status 3 output go tool: no such tool "asm"
FAIL
FAIL    cmd/internal/obj/x86    0.073s

So skip it for now. It's tested in enough other places.

Change-Id: I9a98ad7b8be807005750112d892ac6c676c17dd5
Reviewed-on: https://go-review.googlesource.com/18989
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

src/cmd/internal/obj/x86/obj6_test.go

@@ -150,6 +150,13 @@ func parseOutput(t *testing.T, td *ParsedTestData, asmout []byte) {
 func TestDynlink(t *testing.T) {
 	testenv.MustHaveGoBuild(t)
 
+	if os.Getenv("GOHOSTARCH") != "" {
+		// TODO: make this work? It was failing due to the
+		// GOARCH= filtering above and skipping is easiest for
+		// now.
+		t.Skip("skipping when GOHOSTARCH is set")
+	}
+
 	testdata := parseTestData(t)
 	asmout := asmOutput(t, testdata.input)
 	parseOutput(t, testdata, asmout)