Create a Tree IR builder for JavaScript specific nodes.

pkg/compiler/lib/src/dart_backend/backend.dart

Index: pkg/compiler/lib/src/dart_backend/backend.dart
diff --git a/pkg/compiler/lib/src/dart_backend/backend.dart b/pkg/compiler/lib/src/dart_backend/backend.dart
index 2c8dd77094ee5ea6cf53a99b677e6bcc1d984c5e..d5a2b70e7d90724ebd51a2595dc50350dec81568 100644
--- a/pkg/compiler/lib/src/dart_backend/backend.dart
+++ b/pkg/compiler/lib/src/dart_backend/backend.dart
@@ -162,8 +162,8 @@ class DartBackend extends Backend {
     // ranges that can be invalidated by transforming the IR.
     new cps_ir.RegisterAllocator().visit(cpsDefinition);
 
-    tree_builder.Builder builder = new tree_builder.Builder(
-        new Glue(compiler), compiler.internalError, compiler.identicalFunction);
+    tree_builder.Builder builder =
+        new tree_builder.Builder(compiler.internalError);
     tree_ir.ExecutableDefinition treeDefinition = builder.build(cpsDefinition);
     assert(treeDefinition != null);
     traceGraph('Tree builder', treeDefinition);