dart2js cps: Use definitions by default, not references.

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

Index: pkg/compiler/lib/src/cps_ir/optimize_interceptors.dart
diff --git a/pkg/compiler/lib/src/cps_ir/optimize_interceptors.dart b/pkg/compiler/lib/src/cps_ir/optimize_interceptors.dart
index 689dac67fdd02e4163c1c5dd72904b3bcd08b059..d9c59b683884b5b28e91fc14dde1e8edcb8c3c9c 100644
--- a/pkg/compiler/lib/src/cps_ir/optimize_interceptors.dart
+++ b/pkg/compiler/lib/src/cps_ir/optimize_interceptors.dart
@@ -137,7 +137,7 @@ class OptimizeInterceptors extends TrampolineRecursiveVisitor implements Pass {
     for (Reference ref = node.firstRef; ref != null; ref = ref.next) {
       if (ref.parent is InvokeMethod) {
         InvokeMethod invoke = ref.parent;
-        if (invoke.receiver != ref) return false;
+        if (invoke.receiverRef != ref) return false;
         var interceptedClasses =
             backend.getInterceptedClassesOn(invoke.selector.name);
         if (interceptedClasses.contains(helpers.jsDoubleClass)) return false;
@@ -173,7 +173,7 @@ class OptimizeInterceptors extends TrampolineRecursiveVisitor implements Pass {
     // TODO(asgerf): This could be more precise if we used the use-site type,
     // since the interceptor may have been hoisted out of a loop, where a less
     // precise type is known.
-    Primitive input = node.input.definition;
+    Primitive input = node.input;
     TypeMask type = input.type;
     if (canInterceptNull(node)) return null;
     type = type.nonNullable();
@@ -198,7 +198,7 @@ class OptimizeInterceptors extends TrampolineRecursiveVisitor implements Pass {
   /// successful.
   bool constifyInterceptor(Interceptor interceptor) {
     LetPrim let = interceptor.parent;
-    Primitive input = interceptor.input.definition;
+    Primitive input = interceptor.input;
     ClassElement classElement = getSingleInterceptorClass(interceptor);
 
     if (classElement == null) return false;
@@ -261,7 +261,7 @@ class OptimizeInterceptors extends TrampolineRecursiveVisitor implements Pass {
   @override
   void visitInvokeMethod(InvokeMethod node) {
     if (node.callingConvention != CallingConvention.Intercepted) return;
-    Primitive interceptor = node.receiver.definition;
+    Primitive interceptor = node.receiver;
     if (interceptor is! Interceptor ||
         interceptor.hasMultipleUses ||
         loopHeaderFor[interceptor] != currentLoopHeader) {
@@ -270,12 +270,12 @@ class OptimizeInterceptors extends TrampolineRecursiveVisitor implements Pass {
     // TODO(asgerf): Consider heuristics for when to use one-shot interceptors.
     //   E.g. using only one-shot interceptors with a fast path.
     node.callingConvention = CallingConvention.OneShotIntercepted;
-    node..receiver.unlink()..receiver = node.arguments.removeAt(0);
+    node..receiverRef.unlink()..receiverRef = node.argumentRefs.removeAt(0);
   }
 
   @override
   void visitTypeTestViaFlag(TypeTestViaFlag node) {
-    Primitive interceptor = node.interceptor.definition;
+    Primitive interceptor = node.interceptor;
     if (interceptor is! Interceptor ||
         interceptor.hasMultipleUses ||
         loopHeaderFor[interceptor] != currentLoopHeader ||
@@ -283,7 +283,7 @@ class OptimizeInterceptors extends TrampolineRecursiveVisitor implements Pass {
       return;
     }
     Interceptor inter = interceptor;
-    Primitive value = inter.input.definition;
+    Primitive value = inter.input;
     node.replaceWith(new TypeTest(value, node.dartType, [])..type = node.type);
   }
 }