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

lib/compiler/implementation/ssa/codegen.dart

Index: lib/compiler/implementation/ssa/codegen.dart
diff --git a/lib/compiler/implementation/ssa/codegen.dart b/lib/compiler/implementation/ssa/codegen.dart
index f1bebc7d6573c6a3401121faf622f25e102da7f4..bd4ba4899d2cbe189bab0c22acce0f8b30152b56 100644
--- a/lib/compiler/implementation/ssa/codegen.dart
+++ b/lib/compiler/implementation/ssa/codegen.dart
@@ -1714,30 +1714,33 @@ class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
   }
 
   void generateConstant(Constant constant) {
-    Namer namer = backend.namer;
-    if (!constant.isObject()) {
+    ConstantHandler handler = compiler.constantHandler;
+    String name = handler.getNameForConstant(constant);
+    if (name === null) {
+      assert(!constant.isObject());
       if (constant.isBool()) {
         push(new js.LiteralBool((constant as BoolConstant).value));
       } else if (constant.isNum()) {
         // TODO(floitsch): get rid of the code buffer.
         CodeBuffer buffer = new CodeBuffer();
-        backend.emitter.writeConstantToBuffer(constant, buffer);
+        handler.writeConstant(buffer, constant);
         push(new js.LiteralNumber(buffer.toString()));
       } else if (constant.isNull()) {
         push(new js.LiteralNull());
       } else if (constant.isString()) {
         // TODO(floitsch): get rid of the code buffer.
         CodeBuffer buffer = new CodeBuffer();
-        backend.emitter.writeConstantToBuffer(constant, buffer);
+        handler.writeConstant(buffer, constant);
         push(new js.LiteralString(buffer.toString()));
       } else if (constant.isFunction()) {
         FunctionConstant function = constant;
         world.registerStaticUse(function.element);
-        push(new js.VariableUse(namer.isolateAccess(function.element)));
+        push(new js.VariableUse(
+            backend.namer.isolateAccess(function.element)));
       } else if (constant.isSentinel()) {
         // TODO(floitsch): get rid of the code buffer.
         CodeBuffer buffer = new CodeBuffer();
-        backend.emitter.writeConstantToBuffer(constant, buffer);
+        handler.writeConstant(buffer, constant);
         push(new js.VariableUse(buffer.toString()));
       } else {
         compiler.internalError(
@@ -1745,7 +1748,6 @@ class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
             "constant $constant");
       }
     } else {
-      String name = namer.constantName(constant);
       js.VariableUse currentIsolateUse =
           new js.VariableUse(backend.namer.CURRENT_ISOLATE);
       push(new js.PropertyAccess.field(currentIsolateUse, name));