Convert a == to a builtin identity check if the receiver type can only hit Object==.

sdk/lib/_internal/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.
 
 part of ssa;
 
 abstract class OptimizationPhase {
   String get name;
   void visitGraph(HGraph graph);
 }
@@ skipping 250 matching lines @@
     Operation operation = node.specializer.operation(constantSystem);
     if (operation != null) {
       HInstruction instruction = node.inputs.length == 2
           ? foldUnary(operation, node.inputs[1])
           : foldBinary(operation, node.inputs[1], node.inputs[2]);
       if (instruction != null) return instruction;
     }
 
     // Try converting the instruction to a builtin instruction.
     HInstruction instruction =
-        node.specializer.tryConvertToBuiltin(node);
+        node.specializer.tryConvertToBuiltin(node, compiler);
     if (instruction != null) return instruction;
 
     Selector selector = node.selector;
     var interceptor = node.inputs[0];
     HInstruction input = node.inputs[1];
 
     if (selector.isCall()) {
       Element target;
       if (input.isExtendableArray()) {
         if (selector.applies(backend.jsArrayRemoveLast, compiler)) {
@@ skipping 1281 matching lines @@
     HBasicBlock block = user.block;
     block.addAfter(user, interceptor);
     block.rewrite(user, interceptor);
     block.remove(user);
 
     // The interceptor will be removed in the dead code elimination
     // phase. Note that removing it here would not work because of how
     // the [visitBasicBlock] is implemented.
   }
 }