Version 3.12.19

Performance and stability improvements on all platforms.

git-svn-id: http://v8.googlecode.com/svn/trunk@12243 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
diff --git a/src/x64/macro-assembler-x64.h b/src/x64/macro-assembler-x64.h
index 68795a4..85d58f4 100644
--- a/src/x64/macro-assembler-x64.h
+++ b/src/x64/macro-assembler-x64.h
@@ -1328,6 +1328,8 @@
   // modified. It may be the "smi 1 constant" register.
   Register GetSmiConstant(Smi* value);
 
+  intptr_t RootRegisterDelta(ExternalReference other);
+
   // Moves the smi value to the destination register.
   void LoadSmiConstant(Register dst, Smi* value);