Access ConstantSystem through ClosedWorld.

pkg/compiler/lib/src/ssa/interceptor_simplifier.dart

Index: pkg/compiler/lib/src/ssa/interceptor_simplifier.dart
diff --git a/pkg/compiler/lib/src/ssa/interceptor_simplifier.dart b/pkg/compiler/lib/src/ssa/interceptor_simplifier.dart
index 6855b8c34c57ddd8f6c3bceec93034150910c68f..2d6a1a7c513496c6ecff4e2e9840f1323eaac1b9 100644
--- a/pkg/compiler/lib/src/ssa/interceptor_simplifier.dart
+++ b/pkg/compiler/lib/src/ssa/interceptor_simplifier.dart
@@ -38,18 +38,18 @@ class SsaSimplifyInterceptors extends HBaseVisitor
     implements OptimizationPhase {
   final String name = "SsaSimplifyInterceptors";
   final ClosedWorld closedWorld;
-  final ConstantSystem constantSystem;
   final Compiler compiler;
   final Element element;
   HGraph graph;
 
-  SsaSimplifyInterceptors(
-      this.compiler, this.closedWorld, this.constantSystem, this.element);
+  SsaSimplifyInterceptors(this.compiler, this.closedWorld, this.element);
 
   JavaScriptBackend get backend => compiler.backend;
 
   BackendClasses get backendClasses => closedWorld.backendClasses;
 
+  ConstantSystem get constantSystem => closedWorld.constantSystem;
+
   void visitGraph(HGraph graph) {
     this.graph = graph;
     visitDominatorTree(graph);
@@ -136,7 +136,7 @@ class SsaSimplifyInterceptors extends HBaseVisitor
 
     ConstantValue constant =
         new InterceptorConstantValue(constantInterceptor.thisType);
-    return graph.addConstant(constant, compiler);
+    return graph.addConstant(constant, closedWorld);
   }
 
   ClassElement tryComputeConstantInterceptorFromType(
@@ -320,7 +320,7 @@ class SsaSimplifyInterceptors extends HBaseVisitor
           if (interceptorClass != null) {
             HInstruction constantInstruction = graph.addConstant(
                 new InterceptorConstantValue(interceptorClass.thisType),
-                compiler);
+                closedWorld);
             node.conditionalConstantInterceptor = constantInstruction;
             constantInstruction.usedBy.add(node);
             return false;
@@ -360,7 +360,7 @@ class SsaSimplifyInterceptors extends HBaseVisitor
     } else if (user is HInvokeDynamic) {
       if (node == user.inputs[0]) {
         // Replace the user with a [HOneShotInterceptor].
-        HConstant nullConstant = graph.addConstantNull(compiler);
+        HConstant nullConstant = graph.addConstantNull(closedWorld);
         List<HInstruction> inputs = new List<HInstruction>.from(user.inputs);
         inputs[0] = nullConstant;
         HOneShotInterceptor oneShotInterceptor = new HOneShotInterceptor(