Refactor the collection of initializer list types

lib/compiler/implementation/ssa/optimize.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.
 
 interface OptimizationPhase {
   String get name();
   void visitGraph(HGraph graph);
 }
 
 class SsaOptimizerTask extends CompilerTask {
@@ skipping 1178 matching lines @@
   }
 
   HInstruction visitEquals(HEquals node) {
     // Try to optimize the case where a field which is known to always be an
     // integer is compared with a constant integer literal.
     if (node.left is HFieldGet &&
         node.right is HConstant &&
         node.right.isInteger()) {
       HFieldGet left = node.left;
       HConstant right = node.right;
-      if (left.element != null) {
-        Type type = left.receiver.propagatedType.computeType(compiler);
+      if (left.element != null && left.element.enclosingElement.isClass()) {
         switch (compiler.phase) {
           case Compiler.PHASE_COMPILING:
-            if (compiler.codegenWorld.couldHaveFieldOnlyIntegerSetters(
-                    type, left.element.name) &&
-                compiler.codegenWorld.hasFieldOnlyIntegerInitializers(
-                    type, left.element.name)) {
+            if (backend.onlyFieldIntegerSettersSoFar(left.element) &&
+                backend.couldHaveFieldSingleTypeInitializers(
+                    left.element, HType.INTEGER)) {
               compiler.enqueuer.codegen.registerRecompilationCandidate(
                   work.element);
             }
             break;
           case Compiler.PHASE_RECOMPILING:
-            if (compiler.codegenWorld.hasFieldOnlyIntegerSetters(
-                    type, left.element.name) &&
-                compiler.codegenWorld.hasFieldOnlyIntegerInitializers(
-                    type, left.element.name)) {
+            if (backend.onlyFieldIntegerSettersSoFar(left.element) &&
+                backend.hasFieldSingleTypeInitializers(
+                    left.element, HType.INTEGER)) {
               if (compiler.codegenWorld.hasInvokedSetter(left.element,
                                                          compiler)) {
                 // If there are invoked setters we don't know for sure that the
                 // field will hold an integer, but the fact that the class
                 // itself always sets an integer in the fiels is still a strong
                 // signal to indiate the expected type of the field.
                 left.propagatedType = HType.INTEGER;
                 graph.highTypeLikelyhood = true;
               } else {
                 // If there are no invoked setters we know the type of this
                 // field for sure.
                 left.guaranteedType = HType.INTEGER;
               }
             }
             break;
           default:
             assert(false);
             break;
         }
       }
     }
   }
 }