GDScript: fix regression when checking for virtual function implement…

…ation.

Unfortunately it appears the virtual function checks in godotengine#77324 are not
trustworthy at runtime, because objects can have scripts attached, but
this information is not always available at compile-time. These checks
need to be removed.

The rest of the PR is still useful, making all method flags available to
the analyzer, so a full revert isn't necessary/desirable.

This reopens godotengine#76938, which will need another solution.

modules/gdscript/gdscript_analyzer.cpp

@@ -3097,16 +3097,6 @@ void GDScriptAnalyzer::reduce_call(GDScriptParser::CallNode *p_call, bool p_is_a
 	bool is_constructor = (base_type.is_meta_type || (p_call->callee && p_call->callee->type == GDScriptParser::Node::IDENTIFIER)) && p_call->function_name == SNAME("new");
 
 	if (get_function_signature(p_call, is_constructor, base_type, p_call->function_name, return_type, par_types, default_arg_count, method_flags)) {
-		// If the method is implemented in the class hierarchy, the virtual flag will not be set for that MethodInfo and the search stops there.
-		// MethodInfo's above the class that defines the method might still have the virtual flag set.
-		if (method_flags.has_flag(METHOD_FLAG_VIRTUAL)) {
-			if (p_call->is_super) {
-				push_error(vformat(R"*(Cannot call the parent class' virtual function "%s()" because it hasn't been defined.)*", p_call->function_name), p_call);
-			} else {
-				push_error(vformat(R"*(Cannot call virtual function "%s()" because it hasn't been defined.)*", p_call->function_name), p_call);
-			}
-		}
-
 		// If the function require typed arrays we must make literals be typed.
 		for (const KeyValue<int, GDScriptParser::ArrayNode *> &E : arrays) {
 			int index = E.key;