runtime/pprof: skip tests that fail on windows-amd64-race builder

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/44180043

src/pkg/runtime/pprof/pprof_test.go

@@ -33,6 +33,10 @@ func TestCPUProfile(t *testing.T) {
 }
 
 func TestCPUProfileMultithreaded(t *testing.T) {
+	// TODO(brainman): delete when issue 6986 is fixed.
+	if runtime.GOOS == "windows" && runtime.GOARCH == "amd64" {
+		t.Skip("skipping broken test on windows-amd64-race")
+	}
 	buf := make([]byte, 100000)
 	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(2))
 	testCPUProfile(t, []string{"crc32.ChecksumIEEE", "crc32.Update"}, func() {
@@ -244,6 +248,10 @@ func TestGoroutineSwitch(t *testing.T) {
 
 // Test that profiling of division operations is okay, especially on ARM. See issue 6681.
 func TestMathBigDivide(t *testing.T) {
+	// TODO(brainman): delete when issue 6986 is fixed.
+	if runtime.GOOS == "windows" && runtime.GOARCH == "amd64" {
+		t.Skip("skipping broken test on windows-amd64-race")
+	}
 	testCPUProfile(t, nil, func() {
 		t := time.After(5 * time.Second)
 		pi := new(big.Int)