Support for native in leg, and start moving native tests to a specific test suite.

frog/leg/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.
 
 class SsaCodeGeneratorTask extends CompilerTask {
   SsaCodeGeneratorTask(Compiler compiler) : super(compiler);
   String get name() => 'SSA code generator';
 
   String generate(WorkItem work, HGraph graph) {
     return measure(() {
@@ skipping 518 matching lines @@
         name = "this";
       } else if (input is HParameterValue) {
         HParameterValue parameter = input;
         name = parameterNames[parameter.element];
       } else {
         assert(!input.generateAtUseSite());
         name = temporary(input);
       }
       code = code.replaceAll('\$$i', name);
     }
-    buffer.add('($code)');
+    if (node.generateAtUseSite()) {
+      buffer.add('($code)');
+    } else {
+      buffer.add('$code');
+    }
   }
 
   visitForeignNew(HForeignNew node) {
     String jsClassReference = compiler.namer.isolateAccess(node.element);
     buffer.add('new $jsClassReference(');
     // We can't use 'visitArguments', since our arguments start at input[0].
     List<HInstruction> inputs = node.inputs;
     for (int i = 0; i < inputs.length; i++) {
       if (i != 0) buffer.add(', ');
       use(inputs[i]);
@@ skipping 595 matching lines @@
       startBailoutSwitch();
     }
   }
 
   void endElse(HIf node) {
     if (node.elseBlock.hasBailouts()) {
       endBailoutSwitch();
     }
   }
 }