Revert "Remove JavaScriptBackend from ClosedWorldBase"

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 68c0d561c46ef9e9fe8142f1d960b1dfd3a4b4f1..dad06b9456d53d0db4f49573f5f1353a455116e8 100644
--- a/pkg/compiler/lib/src/ssa/interceptor_simplifier.dart
+++ b/pkg/compiler/lib/src/ssa/interceptor_simplifier.dart
@@ -221,8 +221,8 @@ class SsaSimplifyInterceptors extends HBaseVisitor
         dominator.isCallOnInterceptor(closedWorld) &&
         node == dominator.receiver &&
         useCount(dominator, node) == 1) {
-      interceptedClasses = interceptorData.getInterceptedClassesOn(
-          dominator.selector.name, closedWorld);
+      interceptedClasses =
+          interceptorData.getInterceptedClassesOn(dominator.selector.name);
 
       // If we found that we need number, we must still go through all
       // uses to check if they require int, or double.
@@ -232,8 +232,8 @@ class SsaSimplifyInterceptors extends HBaseVisitor
         Set<ClassEntity> required;
         for (HInstruction user in node.usedBy) {
           if (user is! HInvoke) continue;
-          Set<ClassEntity> intercepted = interceptorData
-              .getInterceptedClassesOn(user.selector.name, closedWorld);
+          Set<ClassEntity> intercepted =
+              interceptorData.getInterceptedClassesOn(user.selector.name);
           if (intercepted.contains(_commonElements.jsIntClass)) {
             // TODO(johnniwinther): Use type argument when all uses of
             // intercepted classes expect entities instead of elements.
@@ -261,14 +261,14 @@ class SsaSimplifyInterceptors extends HBaseVisitor
             user.isCallOnInterceptor(closedWorld) &&
             node == user.receiver &&
             useCount(user, node) == 1) {
-          interceptedClasses.addAll(interceptorData.getInterceptedClassesOn(
-              user.selector.name, closedWorld));
+          interceptedClasses.addAll(
+              interceptorData.getInterceptedClassesOn(user.selector.name));
         } else if (user is HInvokeSuper &&
             user.isCallOnInterceptor(closedWorld) &&
             node == user.receiver &&
             useCount(user, node) == 1) {
-          interceptedClasses.addAll(interceptorData.getInterceptedClassesOn(
-              user.selector.name, closedWorld));
+          interceptedClasses.addAll(
+              interceptorData.getInterceptedClassesOn(user.selector.name));
         } else {
           // Use a most general interceptor for other instructions, example,
           // is-checks and escaping interceptors.
@@ -349,8 +349,7 @@ class SsaSimplifyInterceptors extends HBaseVisitor
       // See if we can rewrite the is-check to use 'instanceof', i.e. rewrite
       // "getInterceptor(x).$isT" to "x instanceof T".
       if (node == user.interceptor) {
-        if (interceptorData.mayGenerateInstanceofCheck(
-            user.typeExpression, closedWorld)) {
+        if (interceptorData.mayGenerateInstanceofCheck(user.typeExpression)) {
           HInstruction instanceofCheck = new HIs.instanceOf(
               user.typeExpression, user.expression, user.instructionType);
           instanceofCheck.sourceInformation = user.sourceInformation;