Fix a couple of bugs with async stack traces

tests/language/language.status

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # This directory contains tests that are intended to show the
 # current state of the language.
 
 [ ($runtime == vm || $runtime == dart_precompiled) && $compiler != dartk && $compiler != dartkp ]
 abstract_beats_arguments2_test/01: Crash # Issue 29171
 
@@ skipping 25 matching lines @@
 
 # Regular bugs which should be fixed.
 duplicate_export_negative_test: Fail # Issue 6134
 
 # Non-contractive types are not supported in the vm.
 cyclic_type_test/02: Fail, OK
 cyclic_type_test/04: Fail, OK
 cyclic_type2_test: Fail, OK
 least_upper_bound_expansive_test/*: Fail, OK
 
+# Skipped temporarily until fixed
+vm/regress_29145_test: Skip # Issue 29145
+
 [ $compiler == none || $compiler == precompiler || $compiler == app_jit ]
 dynamic_prefix_core_test/01: RuntimeError # Issue 12478
 multiline_strings_test: Fail # Issue 23020
 
 deferred_redirecting_factory_test: Fail, Crash # Issue 23408
 redirecting_constructor_initializer_test: RuntimeError # Issue 23488
 
 async_star_regression_2238_test: CompileTimeError, RuntimeError # drt only runtime-errs.
 
 [ ($compiler == none || $compiler == precompiler || $compiler == app_jit) && $checked ]
@@ skipping 261 matching lines @@
 # TODO(zra): Investigate
 vm/regress_28325_test: RuntimeError
 closure_cycles_test: Pass, Crash
 
 [$compiler == dart2analyzer]
 vm/regress_27201_test: SkipByDesign # Loads bad library, so will always crash.
 config_import_corelib_test: StaticWarning, OK
 
 [ ($runtime == vm || $runtime == dart_precompiled || $runtime == dartium || $runtime == drt) && ($compiler == none || $compiler == app_jit || $compiler == precompiler) ]
 await_for_test: RuntimeError # issue 28974