Recover from crash in xcodebuild/ReleaseIA32/generated_tests/language/async_test_constructor4.dart.

dart/pkg/compiler/lib/src/compile_time_constants.dart

Index: dart/pkg/compiler/lib/src/compile_time_constants.dart
diff --git a/dart/pkg/compiler/lib/src/compile_time_constants.dart b/dart/pkg/compiler/lib/src/compile_time_constants.dart
index 24bacbee599ac77e42007a69215e351278bfa496..271ff8da1f47b25e9845f9f29f518e3dbfed3d47 100644
--- a/dart/pkg/compiler/lib/src/compile_time_constants.dart
+++ b/dart/pkg/compiler/lib/src/compile_time_constants.dart
@@ -954,6 +954,7 @@ class ConstructorEvaluator extends CompileTimeConstantEvaluator {
    * parameters (like [:this.x:]), also updates the [fieldValues] map.
    */
   void assignArgumentsToParameters(List<AstConstant> arguments) {
+    if (constructor.isErroneous) return;
     // Assign arguments to parameters.
     FunctionSignature signature = constructor.functionSignature;
     int index = 0;
@@ -1065,6 +1066,7 @@ class ConstructorEvaluator extends CompileTimeConstantEvaluator {
    * native JavaScript constructor.
    */
   void evaluateConstructorFieldValues(List<AstConstant> arguments) {
+    if (constructor.isErroneous) return;
     compiler.withCurrentElement(constructor, () {
       assignArgumentsToParameters(arguments);
       evaluateConstructorInitializers();