[stubs] Port LoadFunctionPrototypeStub to CSA

src/s390/macro-assembler-s390.cc

Index: src/s390/macro-assembler-s390.cc
diff --git a/src/s390/macro-assembler-s390.cc b/src/s390/macro-assembler-s390.cc
index ef82606012a04b5f5d841034509738d10d2375e0..e7f2cb4fcb1af3ca80d8805b2959bfd6f53c37e1 100644
--- a/src/s390/macro-assembler-s390.cc
+++ b/src/s390/macro-assembler-s390.cc
@@ -1966,30 +1966,6 @@ void MacroAssembler::GetMapConstructor(Register result, Register map,
   bind(&done);
 }
 
-void MacroAssembler::TryGetFunctionPrototype(Register function, Register result,
-                                             Register scratch, Label* miss) {
-  // Get the prototype or initial map from the function.
-  LoadP(result,
-        FieldMemOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
-
-  // If the prototype or initial map is the hole, don't return it and
-  // simply miss the cache instead. This will allow us to allocate a
-  // prototype object on-demand in the runtime system.
-  CompareRoot(result, Heap::kTheHoleValueRootIndex);
-  beq(miss);
-
-  // If the function does not have an initial map, we're done.
-  Label done;
-  CompareObjectType(result, scratch, scratch, MAP_TYPE);
-  bne(&done, Label::kNear);
-
-  // Get the prototype from the initial map.
-  LoadP(result, FieldMemOperand(result, Map::kPrototypeOffset));
-
-  // All done.
-  bind(&done);
-}
-
 void MacroAssembler::CallStub(CodeStub* stub, TypeFeedbackId ast_id,
                               Condition cond) {
   DCHECK(AllowThisStubCall(stub));  // Stub calls are not allowed in some stubs.