Stop creating dummy call frames when calling out to C functions

runtime/vm/constants_x64.h

Index: runtime/vm/constants_x64.h
diff --git a/runtime/vm/constants_x64.h b/runtime/vm/constants_x64.h
index 6839b677d8c8016d874d9d681cd0efa0be0d6314..896297c9544febbc7c2de754765b34ae5b35e9ec 100644
--- a/runtime/vm/constants_x64.h
+++ b/runtime/vm/constants_x64.h
@@ -85,6 +85,7 @@ enum RexBits {
 
 // Register aliases.
 const Register TMP = R11;  // Used as scratch register by the assembler.
+const Register CALLEE_SAVED = R13;  // Alias for a callee saved register.

[regis, 2014/02/26 23:53:12]

ditto

[Cutch, 2014/02/27 15:52:37]

Done.

 const Register CTX = R14;  // Caches current context in generated code.
 // Caches object pool pointer in generated code.
 const Register PP = R15;