dart2js cps: Narrow the receiver mask on InvokeMethod.

pkg/compiler/lib/src/cps_ir/type_propagation.dart

Index: pkg/compiler/lib/src/cps_ir/type_propagation.dart
diff --git a/pkg/compiler/lib/src/cps_ir/type_propagation.dart b/pkg/compiler/lib/src/cps_ir/type_propagation.dart
index 5784d3ddf1e613cd186ca88c6cc0b17efe3c56a3..39f33b43de50abd20cfd40031c3834ccac1384e3 100644
--- a/pkg/compiler/lib/src/cps_ir/type_propagation.dart
+++ b/pkg/compiler/lib/src/cps_ir/type_propagation.dart
@@ -1718,6 +1718,9 @@ class TransformingVisitor extends DeepRecursiveVisitor {
     if (specializeSingleUseClosureCall(node)) return;
     if (specializeClosureCall(node)) return;
 
+    node.mask =
+      typeSystem.intersection(node.mask, getValue(getDartReceiver(node)).type);
+
     AbstractValue receiver = getValue(node.receiver.definition);
 
     if (node.receiverIsIntercepted &&
@@ -2743,9 +2746,9 @@ class TypePropagationVisitor implements Visitor {
       case AbstractBool.Maybe:
         setReachable(cont);
         // Narrow type of output to those that survive the cast.
-        TypeMask type = input.type.intersection(
-            typeSystem.subtypesOf(node.dartType),
-            classWorld);
+        TypeMask type = typeSystem.intersection(
+            input.type,
+            typeSystem.subtypesOf(node.dartType));
         setValue(cont.parameters.single, nonConstant(type));
         break;
     }