[ignition] desugar async functions/generators/modules in BytecodeGenerator

test/cctest/interpreter/test-bytecode-generator.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <fstream>
 
 #include "src/v8.h"
 
 #include "src/interpreter/bytecode-array-iterator.h"
 #include "src/interpreter/bytecode-generator.h"
@@ skipping 2353 matching lines @@
       "class A { constructor(...args) { this.args = args; } }\n"
       "new A(0, ...[1, 2, 3]);\n",
 
       "class A { constructor(...args) { this.args = args; } }\n"
       "new A(0, ...[1, 2, 3], 4);\n"};
 
   CHECK(CompareTexts(BuildActual(printer, snippets),
                      LoadGolden("NewAndSpread.golden")));
 }
 
+TEST(AsyncFunctions) {
+  InitializedIgnitionHandleScope scope;
+  BytecodeExpectationsPrinter printer(CcTest::isolate());
+  printer.set_wrap(false);
+  printer.set_test_function_name("f");
+
+  const char* snippets[] = {
+      "async function f() { }\n"
+      "f();\n",
+
+      "async function f() { await 42 }\n"
+      "f();\n",
+
+      "async function f() { for (let x of [42]) await x }\n"
+      "f();\n",
+  };
+
+  CHECK(CompareTexts(BuildActual(printer, snippets),
+                     LoadGolden("AsyncFunctions.golden")));
+}
+
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8