cmd/cgo/internal/testshared: disable gccgo tests on PPC64

Disable PPC64 gccgo tests until issue #60798 is fixed in gcc.

Change-Id: I4d330e3d0ab6d4174ee6d8ff2cbedf53c8c4e3d9
Reviewed-on: https://go-review.googlesource.com/c/go/+/504095
Reviewed-by: Ian Lance Taylor <[email protected]>
Run-TryBot: Paul Murphy <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Bryan Mills <[email protected]>

Author: pmur

src/cmd/cgo/internal/testshared/shared_test.go

@@ -731,6 +731,10 @@ func TestThreeGopathShlibs(t *testing.T) {
 func requireGccgo(t *testing.T) {
 	t.Helper()
 
+	if runtime.GOARCH == "ppc64" || runtime.GOARCH == "ppc64le" {
+		t.Skip("gccgo test skipped on PPC64 until issue #60798 is resolved")
+	}
+
 	gccgoName := os.Getenv("GCCGO")
 	if gccgoName == "" {
 		gccgoName = "gccgo"