os/user: disable TestGroupIds for AIX

The corresponding Go Toolchain patch is CL 164039
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/175079

From-SVN: r270857

gcc/go/gofrontend/MERGE

@@ -1,4 +1,4 @@
-7e590184ae1ebc02e1b2577de00cf4fe842217dc
+208521930c9b5adcfb495799ee01b6aec86c2ccf
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/go/os/user/user_test.go

@@ -129,6 +129,9 @@ func TestLookupGroup(t *testing.T) {
 
 func TestGroupIds(t *testing.T) {
 	checkGroup(t)
+	if runtime.GOOS == "aix" {
+		t.Skip("skipping GroupIds, see golang.org/issue/30563")
+	}
 	if runtime.GOOS == "solaris" {
 		t.Skip("skipping GroupIds, see golang.org/issue/14709")
 	}