Fix Clang deprecated builtins

It seems that Clang and GCC have different interpretations of certain
builtins. So this PR fixes the "deprecated" builtins for Clang, but
keeps them for GCC.

include/godot_cpp/templates/cowdata.hpp

@@ -212,7 +212,11 @@ void CowData<T>::_unref(void *p_data) {
 	}
 	// clean up
 
+#ifdef __clang__
+	if (!__is_trivially_destructible(T)) {
+#else
 	if (!__has_trivial_destructor(T)) {
+#endif
 		uint32_t *count = _get_size();
 		T *data = (T *)(count + 1);
 
@@ -247,7 +251,11 @@ uint32_t CowData<T>::_copy_on_write() {
 		T *_data = (T *)(mem_new);
 
 		// initialize new elements
+#ifdef __clang__
+		if (__is_trivially_copyable(T)) {
+#else
 		if (__has_trivial_copy(T)) {
+#endif
 			memcpy(mem_new, _ptr, current_size * sizeof(T));
 
 		} else {
@@ -310,7 +318,11 @@ Error CowData<T>::resize(int p_size) {
 
 		// construct the newly created elements
 
+#ifdef __clang__
+		if (!__is_trivially_constructible(T)) {
+#else
 		if (!__has_trivial_constructor(T)) {
+#endif
 			T *elems = _get_data();
 
 			for (int i = *_get_size(); i < p_size; i++) {
@@ -321,7 +333,11 @@ Error CowData<T>::resize(int p_size) {
 		*_get_size() = p_size;
 
 	} else if (p_size < current_size) {
+#ifdef __clang__
+		if (!__is_trivially_destructible(T)) {
+#else
 		if (!__has_trivial_destructor(T)) {
+#endif
 			// deinitialize no longer needed elements
 			for (uint32_t i = p_size; i < *_get_size(); i++) {
 				T *t = &_get_data()[i];