Also deal with List.filled in the backend, not just the inferrer and list tracer.

sdk/lib/_internal/compiler/implementation/ssa/builder.dart

Index: sdk/lib/_internal/compiler/implementation/ssa/builder.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/ssa/builder.dart	(revision 24217)
+++ sdk/lib/_internal/compiler/implementation/ssa/builder.dart	(working copy)
@@ -3363,8 +3363,9 @@
     bool isListConstructor = false;
     computeType(element) {
       Element originalElement = elements[send];
-      if (Elements.isFixedListConstructorCall(
-              originalElement, send, compiler)) {
+      if (Elements.isFixedListConstructorCall(originalElement, send, compiler)
+          || Elements.isFilledListConstructorCall(
+                  originalElement, send, compiler)) {
         isListConstructor = true;
         HType inferred =
             new HType.inferredForNode(currentElement, send, compiler);