runtime: skip testSetPanicOnFault for gollvm

LLVM doesn't support non-call exception. This test was passing
    more or less by luck: if the faulting instruction is between two
    calls with the same landing pad (in instruction layout order,
    not the program's logic order), it generates a merged PC range
    that covers the faulting instruction. If the instruction layout
    order changes, or it uses two different (but may be degenerate)
    landing pads, this doesn't work.
    
    Reviewed-on: https://go-review.googlesource.com/c/140517

From-SVN: r264985

gcc/go/gofrontend/MERGE

@@ -1,4 +1,4 @@
-a9da4d34a2f878a5058f7e7d2beef52aa62471a1
+e32e9aaee598eeb43f9616cf6ca1d11acaa9d167
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/go/runtime/runtime_test.go

@@ -166,6 +166,9 @@ func TestSetPanicOnFault(t *testing.T) {
 }
 
 func testSetPanicOnFault(t *testing.T, addr uintptr, nfault *int) {
+	if strings.Contains(Version(), "llvm") {
+		t.Skip("LLVM doesn't support non-call exception")
+	}
 	if GOOS == "nacl" {
 		t.Skip("nacl doesn't seem to fault on high addresses")
 	}