Fix wrong assumptions I had on the isolate library.

frog/leg/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 1706 matching lines @@
         enableMethodInterception();
         break;
       case "JS_HAS_EQUALS":
         List<HInstruction> inputs = <HInstruction>[];
         if (!node.arguments.tail.isEmpty()) {
           compiler.cancel('More than one expression in JS_HAS_EQUALS()');
         }
         addGenericSendArgumentsToList(node.arguments, inputs);
         String name = compiler.namer.instanceMethodName(
             Namer.OPERATOR_EQUALS, 1);
-        push(new HForeign(new DartString.literal('#.$name'),
+        push(new HForeign(new DartString.literal('!!#.$name'),

[ngeoffray, 2012/03/15 12:15:39]

In case we don't propagate types, the check will return false, ie the previous
code will generate:

if (a.operator$eq$1 === true) { ... }

Which is obviously wrong because a.operator$eq$1 is either undefined or a
function.

                           const LiteralDartString('bool'),
                           inputs));
         break;
       case "native":
         native.handleSsaNative(this, node);
         break;
       default:
         throw "Unknown foreign: ${node.selector}";
     }
   }
@@ skipping 782 matching lines @@
     buildBody() {
       // TODO(lrn): Make sure to take continue into account.
       visit(body);
       if (isAborted()) {
         compiler.reportWarning(body, "aborting loop body");
       }
     }
     handleIf(buildBody, null);
   }
 }