Address long-standing review comments.

sdk/lib/_internal/compiler/implementation/resolution/members.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 resolution;
 
 abstract class TreeElements {
   Element get currentElement;
   Set<Node> get superUses;
 
@@ skipping 2267 matching lines @@
         // Set the type of the node to [Type] to mark this send as a
         // type literal.
         mapping.setType(node, compiler.typeClass.computeType(compiler));
         world.registerTypeLiteral(target, mapping);
       }
     }
 
     bool resolvedArguments = false;
     if (node.isOperator) {
       String operatorString = node.selector.asOperator().source.stringValue;
-      if (operatorString == 'is') {
+      if (identical(operatorString, 'is')) {
         DartType type =
             resolveTypeExpression(node.typeAnnotationFromIsCheckOrCast);
         if (type != null) {
           compiler.enqueuer.resolution.registerIsCheck(type, mapping);
         }
         resolvedArguments = true;
-      } else if (operatorString == 'as') {
+      } else if (identical(operatorString, 'as')) {
         DartType type = resolveTypeExpression(node.arguments.head);
         if (type != null) {
           compiler.enqueuer.resolution.registerAsCheck(type, mapping);
         }
         resolvedArguments = true;
       }
     }
 
     if (!resolvedArguments) {
       oldSendIsMemberAccess = sendIsMemberAccess;
@@ skipping 269 matching lines @@
     world.registerInstantiatedClass(
         redirectionTarget.enclosingElement.declaration, mapping);
     if (isSymbolConstructor) {
       // Make sure that collection_dev.Symbol.validated is registered.
       assert(invariant(node, compiler.symbolValidatedConstructor != null));
       world.registerStaticUse(compiler.symbolValidatedConstructor);
     }
   }
 
   visitThrow(Throw node) {
-    // We don't know ahead of time whether we will need the throw in a
-    // statement context or an expression context, so we register both
-    // here, even though we may not need ThrowExpression.
-    compiler.backend.registerWrapException(mapping);
     compiler.backend.registerThrowExpression(mapping);
     visit(node.expression);
   }
 
   visitVariableDefinitions(VariableDefinitions node) {
     VariableDefinitionsVisitor visitor =
         new VariableDefinitionsVisitor(compiler, node, this,
                                        ElementKind.VARIABLE);
     // Ensure that we set the type of the [VariableListElement] since it depends
     // on the current scope. If the current scope is a [MethodScope] or
@@ skipping 1492 matching lines @@
     return e;
   }
 
   /// Assumed to be called by [resolveRedirectingFactory].
   Element visitReturn(Return node) {
     Node expression = node.expression;
     return finishConstructorReference(visit(expression),
                                       expression, expression);
   }
 }