[stubs] Port LoadFunctionPrototypeStub to CSA

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 58455bec027c3468cabbd881cacb4019b5a68a0b..866e86076bb87adab23f3e6604c26f1ba4cf8e3b 100644
--- a/src/x64/macro-assembler-x64.h
+++ b/src/x64/macro-assembler-x64.h
@@ -1353,13 +1353,6 @@ class MacroAssembler: public Assembler {
   // |temp| holds |result|'s map when done.
   void GetMapConstructor(Register result, Register map, Register temp);
 
-  // Try to get function prototype of a function and puts the value in
-  // the result register. Checks that the function really is a
-  // function and jumps to the miss label if the fast checks fail. The
-  // function register will be untouched; the other register may be
-  // clobbered.
-  void TryGetFunctionPrototype(Register function, Register result, Label* miss);
-
   // Find the function context up the context chain.
   void LoadContext(Register dst, int context_chain_length);