dart2js: Fix hints in code base.

pkg/compiler/lib/src/ssa/codegen.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;
 
 class SsaCodeGeneratorTask extends CompilerTask {
 
   final JavaScriptBackend backend;
   final SourceInformationFactory sourceInformationFactory;
@@ skipping 1489 matching lines @@
       use(node.receiver);
       List<js.Expression> arguments = <js.Expression>[pop()];
       push(js.propertyCall(isolate, name, arguments), node);
       registry.registerUseInterceptor();
     }
   }
 
   visitInvokeDynamicMethod(HInvokeDynamicMethod node) {
     use(node.receiver);
     js.Expression object = pop();
-    String name = node.selector.name;
     String methodName;
     List<js.Expression> arguments = visitArguments(node.inputs);
     Element target = node.element;
 
     if (target != null && !node.isInterceptedCall) {
       if (target == backend.jsArrayAdd) {
         methodName = 'push';
       } else if (target == backend.jsArrayRemoveLast) {
         methodName = 'pop';
       } else if (target == backend.jsStringSplit) {
@@ skipping 364 matching lines @@
       ">=" : "<"
     };
     return inverse ? inverseOperator[op] : op;
   }
 
   void generateNot(HInstruction input) {
     bool canGenerateOptimizedComparison(HInstruction instruction) {
       if (instruction is !HRelational) return false;
 
       HRelational relational = instruction;
-      BinaryOperation operation = relational.operation(backend.constantSystem);
 
       HInstruction left = relational.left;
       HInstruction right = relational.right;
       if (left.isStringOrNull(compiler) && right.isStringOrNull(compiler)) {
         return true;
       }
 
       // This optimization doesn't work for NaN, so we only do it if the
       // type is known to be an integer.
       return left.isInteger(compiler) && right.isInteger(compiler);
@@ skipping 547 matching lines @@
     // be changed to match.
     assert(relation == '===' || relation == '!==');
     bool negative = relation == '!==';
 
     if (node.isVariableCheck || node.isCompoundCheck) {
       use(node.checkCall);
       if (negative) push(new js.Prefix('!', pop()));
     } else {
       assert(node.isRawCheck);
       HInstruction interceptor = node.interceptor;
-      LibraryElement coreLibrary = compiler.coreLibrary;
       ClassElement objectClass = compiler.objectClass;
       Element element = type.element;
       if (element == compiler.nullClass) {
         if (negative) {
           checkNonNull(input);
         } else {
           checkNull(input);
         }
       } else if (identical(element, objectClass) || type.treatAsDynamic) {
         // The constant folder also does this optimization, but we make
@@ skipping 254 matching lines @@
   js.PropertyAccess accessHelper(String name) {
     Element helper = backend.findHelper(name);
     if (helper == null) {
       // For mocked-up tests.
       return js.js('(void 0).$name');
     }
     registry.registerStaticUse(helper);
     return backend.emitter.staticFunctionAccess(helper);
   }
 }