Change assert implementation to not depend on a top-level function called 'assert'.

lib/compiler/implementation/js_backend/namer.dart

Index: lib/compiler/implementation/js_backend/namer.dart
diff --git a/lib/compiler/implementation/js_backend/namer.dart b/lib/compiler/implementation/js_backend/namer.dart
index c07c6cffedb606813332629d9c8154efd906ebdd..50f678f4e7f393aaa9b31330e3f011746b7b8344 100644
--- a/lib/compiler/implementation/js_backend/namer.dart
+++ b/lib/compiler/implementation/js_backend/namer.dart
@@ -18,17 +18,14 @@ class Namer {
     return _jsReserved;
   }
 
-  final Map<Element, String> globals;
-  final Map<String, int> usedGlobals;
-  final Map<String, LibraryElement> shortPrivateNameOwners;
-
-  final Map<Constant, String> constantNames;
+  Map<Element, String> globals;
+  Map<String, int> usedGlobals;
+  Map<String, LibraryElement> shortPrivateNameOwners;
 
   Namer(this.compiler)
       : globals = new Map<Element, String>(),
         usedGlobals = new Map<String, int>(),
-        shortPrivateNameOwners = new Map<String, LibraryElement>(),
-        constantNames = new Map<Constant, String>();
+        shortPrivateNameOwners = new Map<String, LibraryElement>();
 
   final String CURRENT_ISOLATE = @'$';
   final String ISOLATE = 'Isolate';
@@ -39,18 +36,6 @@ class Namer {
   static const SourceString CLOSURE_INVOCATION_NAME =
       Compiler.CALL_OPERATOR_NAME;
 
-  String constantName(Constant constant) {
-    // In the current implementation it doesn't make sense to give names to
-    // function constants since the function-implementation itself serves as
-    // constant and can be accessed directly.
-    assert(!constant.isFunction());
-    String result = constantNames[constant];
-    if (result === null) {
-      result = getFreshGlobalName("CTC");
-      constantNames[constant] = result;
-    }
-    return result;
-  }
 
   String closureInvocationName(Selector selector) {
     // TODO(floitsch): mangle, while not conflicting with instance names.