Fix port_test.cc in optimized builds

In optimized builds, this test currently calls `__builtin_assume()` on a false
statement, which is undefined behavior that trips up ubsan. This change fixes
that by skipping the test case when `NDEBUG` is defined.

PiperOrigin-RevId: 721617118

src/google/protobuf/port_test.cc

@@ -25,10 +25,17 @@ int assume_var_for_test = 1;
 TEST(PortTest, ProtobufAssume) {
   PROTOBUF_ASSUME(assume_var_for_test == 1);
 #ifdef GTEST_HAS_DEATH_TEST
+#if defined(NDEBUG)
+  // If NDEBUG is defined, then instead of reliably crashing, the code below
+  // will assume a false statement. This is undefined behavior which will trip
+  // up sanitizers.
+  GTEST_SKIP() << "Can't test PROTOBUF_ASSUME()";
+#else
   EXPECT_DEBUG_DEATH(
       PROTOBUF_ASSUME(assume_var_for_test == 2),
       "port_test\\.cc:.*Assumption failed: 'assume_var_for_test == 2'");
 #endif
+#endif
 }
 
 TEST(PortTest, UnreachableTrapsOnDebugMode) {