Move array and string related HType from const to a field in the backend.

sdk/lib/_internal/compiler/implementation/js_backend/backend.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of js_backend;
 
 class JavaScriptItemCompilationContext extends ItemCompilationContext {
   final Set<HInstruction> boundsChecked;
 
   JavaScriptItemCompilationContext()
@@ skipping 51 matching lines @@
   Element jsStringToString;
   Element objectEquals;
 
   ClassElement typeLiteralClass;
   ClassElement mapLiteralClass;
   ClassElement constMapLiteralClass;
 
   Element getInterceptorMethod;
   Element interceptedNames;
 
+  HType stringType;
+  HType indexablePrimitiveType;
+  HType readableArrayType;
+  HType mutableArrayType;
+  HType fixedArrayType;
+  HType extendableArrayType;
+  
+
   // TODO(9577): Make it so that these are not needed when there are no native
   // classes.
   Element dispatchPropertyName;
   Element getNativeInterceptorMethod;
   Element defineNativeMethodsFinishMethod;
   Element getDispatchPropertyMethod;
   Element setDispatchPropertyMethod;
   Element initializeDispatchPropertyMethod;
   bool needToInitializeDispatchProperty = false;
 
@@ skipping 282 matching lines @@
 
     objectEquals = compiler.lookupElementIn(
         compiler.objectClass, const SourceString('=='));
 
     specialOperatorEqClasses
         ..add(compiler.objectClass)
         ..add(jsInterceptorClass)
         ..add(jsNullClass);
 
     validateInterceptorImplementsAllObjectMethods(jsInterceptorClass);
+
+    stringType = new HBoundedType(
+        new TypeMask.nonNullExact(jsStringClass.rawType));
+    indexablePrimitiveType = new HBoundedType(
+        new TypeMask.nonNullSubtype(jsIndexableClass.rawType));
+    readableArrayType = new HBoundedType(
+        new TypeMask.nonNullSubclass(jsArrayClass.rawType));
+    mutableArrayType = new HBoundedType(
+        new TypeMask.nonNullSubclass(jsMutableArrayClass.rawType));
+    fixedArrayType = new HBoundedType(
+        new TypeMask.nonNullExact(jsFixedArrayClass.rawType));
+    extendableArrayType = new HBoundedType(
+        new TypeMask.nonNullExact(jsExtendableArrayClass.rawType));
   }
 
   void validateInterceptorImplementsAllObjectMethods(
       ClassElement interceptorClass) {
     if (interceptorClass == null) return;
     interceptorClass.ensureResolved(compiler);
     compiler.objectClass.forEachMember((_, Element member) {
       if (member.isGenerativeConstructor()) return;
       Element interceptorMember = interceptorClass.lookupMember(member.name);
       // Interceptors must override all Object methods due to calling convention
@@ skipping 697 matching lines @@
   ClassElement get listImplementation => jsArrayClass;
   ClassElement get constListImplementation => jsArrayClass;
   ClassElement get fixedListImplementation => jsFixedArrayClass;
   ClassElement get growableListImplementation => jsExtendableArrayClass;
   ClassElement get mapImplementation => mapLiteralClass;
   ClassElement get constMapImplementation => constMapLiteralClass;
   ClassElement get typeImplementation => typeLiteralClass;
   ClassElement get boolImplementation => jsBoolClass;
   ClassElement get nullImplementation => jsNullClass;
 }