Update dart2js diagnostics to prepare for filtering.

sdk/lib/_internal/compiler/implementation/typechecker.dart

Index: sdk/lib/_internal/compiler/implementation/typechecker.dart
diff --git a/sdk/lib/_internal/compiler/implementation/typechecker.dart b/sdk/lib/_internal/compiler/implementation/typechecker.dart
index f28f2b2f3d9d88f937a955feb0246c1a1b3bcc4d..52c7baf54b4f0de7dcac37e96fc6058bd4b85a96 100644
--- a/sdk/lib/_internal/compiler/implementation/typechecker.dart
+++ b/sdk/lib/_internal/compiler/implementation/typechecker.dart
@@ -316,8 +316,7 @@ class TypeCheckerVisitor extends Visitor<DartType> {
 
   reportTypeWarning(Spannable spannable, MessageKind kind,
                     [Map arguments = const {}]) {
-    compiler.reportWarning(
-        spannable, new TypeWarning(kind, arguments, compiler.terseDiagnostics));
+    compiler.reportWarning(spannable, kind, arguments);
   }
 
   reportTypeInfo(Spannable spannable, MessageKind kind,