Revert "Wat if you closure identical?"

sdk/lib/_internal/compiler/implementation/lib/core_patch.dart

Index: sdk/lib/_internal/compiler/implementation/lib/core_patch.dart
diff --git a/sdk/lib/_internal/compiler/implementation/lib/core_patch.dart b/sdk/lib/_internal/compiler/implementation/lib/core_patch.dart
index e7054ceef548c634edd964c0125295436043194d..b375a97708abe37844650ba5002f2728232b0e36 100644
--- a/sdk/lib/_internal/compiler/implementation/lib/core_patch.dart
+++ b/sdk/lib/_internal/compiler/implementation/lib/core_patch.dart
@@ -213,6 +213,6 @@ patch class RegExp {
 }
 
 // Patch for 'identical' function.
-// This is very magical: the compiler knows how to optimize a call to
-// identical, so we can just express identical in terms of itself.
-patch bool identical(Object a, Object b) => identical(a, b);
+patch bool identical(Object a, Object b) {
+  throw new Error('Should not reach the body of identical');
+}