Tweak the compilation condition for IsHashableTest.PoisonHash

#1359

PiperOrigin-RevId: 502597369
Change-Id: I5d65ed7e2dbe4b51ebce47f282ead89d91d919cd

absl/hash/hash_test.cc

@@ -904,8 +904,8 @@ TEST(IsHashableTest, PoisonHash) {
   EXPECT_FALSE(absl::is_copy_assignable<absl::Hash<X>>::value);
   EXPECT_FALSE(absl::is_move_assignable<absl::Hash<X>>::value);
   EXPECT_FALSE(IsHashCallable<X>::value);
-#if !defined(__GNUC__) || __GNUC__ < 9
-  // This doesn't compile on GCC 9.
+#if !defined(__GNUC__) || defined(__clang__)
+  // TODO(b/144368551): As of GCC 8.4 this does not compile.
   EXPECT_FALSE(IsAggregateInitializable<absl::Hash<X>>::value);
 #endif
 }