LibJS/Bytecode: Propagate FunctionDeclarationInstantiation exceptions

If an exception is thrown by FunctionDeclarationInstantiation for an
async or async-generator function, we still need to return a promise.
We can't just throw the exception.

81 new passes on test262. :^)

Userland/Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp

@@ -861,10 +861,22 @@ Completion ECMAScriptFunctionObject::ordinary_call_evaluate_body()
             }
         }
 
-        TRY(function_declaration_instantiation(nullptr));
+        auto declaration_result = function_declaration_instantiation(nullptr);
 
-        if (!m_bytecode_executable) {
+        if (m_kind == FunctionKind::Normal || m_kind == FunctionKind::Generator) {
+            if (declaration_result.is_error())
+                return declaration_result.release_error();
+        }
+
+        if (!m_bytecode_executable)
             m_bytecode_executable = TRY(Bytecode::compile(vm, *m_ecmascript_code, m_kind, m_name));
+
+        if (m_kind == FunctionKind::Async || m_kind == FunctionKind::AsyncGenerator) {
+            if (declaration_result.is_throw_completion()) {
+                auto promise_capability = MUST(new_promise_capability(vm, realm.intrinsics().promise_constructor()));
+                MUST(call(vm, *promise_capability->reject(), js_undefined(), *declaration_result.throw_completion().value()));
+                return Completion { Completion::Type::Return, promise_capability->promise(), {} };
+            }
         }
 
         auto result_and_frame = bytecode_interpreter->run_and_return_frame(realm, *m_bytecode_executable, nullptr);