[es6] Tail calls support.

src/x64/macro-assembler-x64.h

Index: src/x64/macro-assembler-x64.h
diff --git a/src/x64/macro-assembler-x64.h b/src/x64/macro-assembler-x64.h
index 4b7b70687100ee96991b3d25a2eed1f5f06c0e3a..a7027ce702c59556cc418e260cb3c9f5cf83e832 100644
--- a/src/x64/macro-assembler-x64.h
+++ b/src/x64/macro-assembler-x64.h
@@ -365,6 +365,9 @@ class MacroAssembler: public Assembler {
   // ---------------------------------------------------------------------------
   // JavaScript invokes
 
+  void DropCurrentJSFrame(Register args, Register scratch1, Register scratch2,

[Benedikt Meurer, 2016/01/21 05:20:49]

Nit: The name is a bit misleading, since this not only drops the "current JS
frame", but might also remove the arguments adaptor frame. I don't have a great
suggestion yet, tho.

[Igor Sheludko, 2016/01/21 14:37:08]

PrepareForTailCall is a better name. Done.

+                          Register scratch3);
+
   // Invoke the JavaScript function code by either calling or jumping.
   void InvokeFunctionCode(Register function, Register new_target,
                           const ParameterCount& expected,