Revert r11753.

src/assembler.h

Index: src/assembler.h
diff --git a/src/assembler.h b/src/assembler.h
index 619c69c4b2abe3a2fb9bd383db9e67b8833d815f..b935ab55eab771efa4bafc54d95fba47d3ffb3f8 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -640,9 +640,6 @@ class ExternalReference BASE_EMBEDDED {
   static ExternalReference handle_scope_level_address();
 
   static ExternalReference scheduled_exception_address(Isolate* isolate);
-  static ExternalReference address_of_pending_message_obj(Isolate* isolate);
-  static ExternalReference address_of_has_pending_message(Isolate* isolate);
-  static ExternalReference address_of_pending_message_script(Isolate* isolate);
 
   // Static variables containing common double constants.
   static ExternalReference address_of_min_int();