LibJS: Always init arguments stored in locals for generator functions

Since AST interpreter switches to bytecode to execute generator
functions, arguments stored in local variables always need to be
initialized for such functions.

Userland/Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp

@@ -479,7 +479,7 @@ ThrowCompletionOr<void> ECMAScriptFunctionObject::function_declaration_instantia
                 Environment* used_environment = has_duplicates ? nullptr : environment;
 
                 if constexpr (IsSame<NonnullRefPtr<Identifier const> const&, decltype(param)>) {
-                    if (vm.bytecode_interpreter_if_exists() && param->is_local()) {
+                    if ((vm.bytecode_interpreter_if_exists() || kind() == FunctionKind::Generator) && param->is_local()) {
                         // NOTE: Local variables are supported only in bytecode interpreter
                         callee_context.local_variables[param->local_variable_index()] = argument_value;
                         return {};