Typecheck const classes in the context of the constructor call.

tests/compiler/dart2js/compiler_helper.dart

Index: tests/compiler/dart2js/compiler_helper.dart
diff --git a/tests/compiler/dart2js/compiler_helper.dart b/tests/compiler/dart2js/compiler_helper.dart
index e139a0eedc412a979260f2c49ac1f11fd8779450..374cf5fa96f669f57af633599ae978e8bbffcd64 100644
--- a/tests/compiler/dart2js/compiler_helper.dart
+++ b/tests/compiler/dart2js/compiler_helper.dart
@@ -95,6 +95,7 @@ MockCompiler compilerFor(String code, Uri uri,
                           bool disableInlining: true,
                           bool minify: false,
                           bool trustTypeAnnotations: false,
+                          bool enableTypeAssertions: false,
                           int expectedErrors,
                           int expectedWarnings,
                           api.CompilerOutputProvider outputProvider}) {
@@ -105,6 +106,7 @@ MockCompiler compilerFor(String code, Uri uri,
       disableInlining: disableInlining,
       enableMinification: minify,
       trustTypeAnnotations: trustTypeAnnotations,
+      enableTypeAssertions: enableTypeAssertions,
       expectedErrors: expectedErrors,
       expectedWarnings: expectedWarnings,
       outputProvider: outputProvider);