X64: Implement DoCallConstantFunction, DoLeaveInlined and DoCompareMap

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 e868cf0a655906f0d1beb5b1311e2943ffdcf1e4..0ee3933708a2a662d573b51c4036ea5675043194 100644
--- a/src/x64/macro-assembler-x64.h
+++ b/src/x64/macro-assembler-x64.h
@@ -604,6 +604,12 @@ class MacroAssembler: public Assembler {
   void Call(ExternalReference ext);
   void Call(Handle<Code> code_object, RelocInfo::Mode rmode);
 
+  // Emit call to the code we are currently generating.
+  void CallSelf() {
+    Handle<Code> self(reinterpret_cast<Code**>(CodeObject().location()));
+    call(self, RelocInfo::CODE_TARGET);
+  }
+
   // Non-x64 instructions.
   // Push/pop all general purpose registers.
   // Does not push rsp/rbp nor any of the assembler's special purpose registers