Collect the types used in is-checks in the resolver phase.

lib/compiler/implementation/ssa/builder.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.
 
 class Interceptors {
   Compiler compiler;
   Interceptors(Compiler this.compiler);
 
   SourceString mapOperatorToMethodName(Operator op) {
     String name = op.source.stringValue;
@@ skipping 2592 matching lines @@
     HInstruction errorMessage = graph.addConstantString(messageObject, node);
     Element helper = interceptors.getThrowRuntimeError();
     pushInvokeHelper1(helper, errorMessage);
   }
 
   visitNewExpression(NewExpression node) {
     Element element = elements[node.send];
     if (element != null && element.isErroneous()) {
       ErroneousElement error = element;
       Message message = error.errorMessage;
-      if (message.kind === MessageKind.CANNOT_FIND_CONSTRUCTOR) {
+      if (message.kind == MessageKind.CANNOT_FIND_CONSTRUCTOR) {
         Element helper =
             compiler.findHelper(const SourceString('throwNoSuchMethod'));
         DartString receiverLiteral = new DartString.literal('');
         HInstruction receiver = graph.addConstantString(receiverLiteral, node);
         String constructorName = 'constructor ${message.arguments[0]}';
         DartString nameLiteral = new DartString.literal(constructorName);
         HInstruction name = graph.addConstantString(nameLiteral, node.send);
         List<HInstruction> inputs = <HInstruction>[];
         node.send.arguments.forEach((argumentNode) {
           visit(argumentNode);
           HInstruction value = pop();
           inputs.add(value);
         });
         HInstruction arguments = new HLiteralList(inputs);
         add(arguments);
         pushInvokeHelper3(helper, receiver, name, arguments);
-      } else if (message.kind === MessageKind.CANNOT_RESOLVE) {
+      } else if (message.kind == MessageKind.CANNOT_RESOLVE) {
         generateRuntimeError(node.send, message.message);
       } else {
         compiler.internalError('unexpected unresolved constructor call',
                                node: node);
       }
     } else if (node.isConst()) {
       // TODO(karlklose): add type representation
       ConstantHandler handler = compiler.constantHandler;
       Constant constant = handler.compileNodeWithDefinitions(node, elements);
       stack.add(graph.addConstant(constant));
@@ skipping 1298 matching lines @@
           new HSubGraphBlockInformation(elseBranch.graph));
 
     HBasicBlock conditionStartBlock = conditionBranch.block;
     conditionStartBlock.setBlockFlow(info, joinBlock);
     SubGraph conditionGraph = conditionBranch.graph;
     HIf branch = conditionGraph.end.last;
     assert(branch is HIf);
     branch.blockInformation = conditionStartBlock.blockFlow;
   }
 }