dart2js cps: Use definitions by default, not references.

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

Index: pkg/compiler/lib/src/cps_ir/cps_ir_integrity.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_integrity.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_integrity.dart
index a2959025b8358e2af077f2134e37a00c74a6c348..8fb65a2e83840c87a4906edf6436562c63882a11 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_integrity.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_integrity.dart
@@ -110,7 +110,7 @@ class CheckCpsIntegrity extends TrampolineRecursiveVisitor {
   @override
   Expression traverseLetMutable(LetMutable node) {
     handleDeclaration(node.variable);
-    processReference(node.value);
+    processReference(node.valueRef);
 
     // Put the primitive in scope when visiting the body.
     enterScope([node.variable]);
@@ -166,7 +166,7 @@ class CheckCpsIntegrity extends TrampolineRecursiveVisitor {
 
   @override
   processInvokeContinuation(InvokeContinuation node) {
-    Continuation target = node.continuation.definition;
+    Continuation target = node.continuation;
     if (node.isRecursive && inScope[target] == ScopeType.InScope) {
       error('Non-recursive InvokeContinuation marked as recursive', node);
     }
@@ -176,7 +176,7 @@ class CheckCpsIntegrity extends TrampolineRecursiveVisitor {
     if (node.isRecursive && !target.isRecursive) {
       error('Recursive Continuation was not marked as recursive', node);
     }
-    if (node.arguments.length != target.parameters.length) {
+    if (node.argumentRefs.length != target.parameters.length) {
       error('Arity mismatch in InvokeContinuation', node);
     }
   }