Support async/await in dart2dart.

tests/language/language.status

Index: tests/language/language.status
diff --git a/tests/language/language.status b/tests/language/language.status
index 9bd5f58fa9d114e821d4574e33f376b7f59f06d4..2c5483645583980bd9d508d40efab2e3f861f5d4 100644
--- a/tests/language/language.status
+++ b/tests/language/language.status
@@ -7,6 +7,7 @@
 
 [ $compiler == none ]
 built_in_identifier_prefix_test: Fail # Issue 6970
+async_await_syntax_test/b00a: MissingCompileTimeError # Issue 21404
 
 # These bugs refer currently ongoing language discussions.
 constructor_initializer_test/none: Fail # Issue 12633
@@ -18,19 +19,9 @@ closure_in_initializer_test: Fail # Issue 6422
 duplicate_export_negative_test: Fail # Issue 6134
 
 [ $compiler == dart2dart ]
-async_control_structures_test: CompileTimeError # Issue 22051
-async_test/none: CompileTimeError # Issue 22051
-async_test/type-mismatch1: CompileTimeError # Issue 22051
-async_test/type-mismatch2: CompileTimeError # Issue 22051
-async_test/type-mismatch3: CompileTimeError # Issue 22051
-async_test/type-mismatch4: CompileTimeError # Issue 22051
-await_backwards_compatibility_test/none: CompileTimeError # Issue 22051
-await_exceptions_test: CompileTimeError # Issue 22051
-await_for_test: CompileTimeError # Issue 22051
-await_future_test: CompileTimeError # Issue 22051
-await_nonfuture_test: CompileTimeError # Issue 22051
-await_regression_test: CompileTimeError # Issue 22051
-await_test: CompileTimeError # Issue 22051
+async_test/constructor2: MissingCompileTimeError # Issue 22051
+async_test/constructor3: MissingCompileTimeError # Issue 22051
+async_test/setter1: MissingCompileTimeError # Issue 22051
 
 deferred_load_library_wrong_args_test/none: Fail # Issue 17523
 deferred_load_inval_code_test: Fail # Issue 17523
@@ -54,9 +45,38 @@ cyclic_type2_test: Fail, OK
 least_upper_bound_expansive_test/*: Fail, OK
 
 compile_time_constant12_test: Fail # Issue 21000
+async_await_syntax_test/a07a: CompileTimeError # Issue 21404
+async_await_syntax_test/a08a: CompileTimeError # Issue 21404
+async_await_syntax_test/a09a: CompileTimeError # Issue 21404
+async_await_syntax_test/a10a: CompileTimeError # Issue 21404
+async_await_syntax_test/b07a: CompileTimeError # Issue 21404
+async_await_syntax_test/b08a: CompileTimeError # Issue 21404
+async_await_syntax_test/b09a: CompileTimeError # Issue 21404
+async_await_syntax_test/b10a: CompileTimeError # Issue 21404
+async_await_syntax_test/c07a: CompileTimeError # Issue 21404
+async_await_syntax_test/c08a: CompileTimeError # Issue 21404
+async_await_syntax_test/c09a: CompileTimeError # Issue 21404
+async_await_syntax_test/c10a: CompileTimeError # Issue 21404
+async_await_syntax_test/d07a: CompileTimeError # Issue 21404
+async_await_syntax_test/d08a: CompileTimeError # Issue 21404
+async_await_syntax_test/d08b: CompileTimeError # Issue 21404
+async_await_syntax_test/d09a: CompileTimeError # Issue 21404
+async_await_syntax_test/d10a: CompileTimeError # Issue 21404
 
 [ $compiler == none || ($compiler == dart2dart && $builder_tag != new_backend) ]
 compile_time_constant_c_test/01: Fail # Issue 21000
+async_await_syntax_test/a03a: CompileTimeError # Issue 21404
+async_await_syntax_test/a04a: CompileTimeError # Issue 21404
+async_await_syntax_test/a11b: CompileTimeError # Issue 21404
+async_await_syntax_test/a11d: CompileTimeError # Issue 21404
+async_await_syntax_test/b03a: CompileTimeError # Issue 21404
+async_await_syntax_test/b04a: CompileTimeError # Issue 21404
+async_await_syntax_test/b11b: CompileTimeError # Issue 21404
+async_await_syntax_test/b11d: CompileTimeError # Issue 21404
+async_await_syntax_test/c03a: CompileTimeError # Issue 21404
+async_await_syntax_test/c04a: CompileTimeError # Issue 21404
+async_await_syntax_test/d03a: CompileTimeError # Issue 21404
+async_await_syntax_test/d04a: CompileTimeError # Issue 21404
 
 [ $compiler == none && $runtime == vm ]
 class_keyword_test/02: MissingCompileTimeError # Issue 13627