[stubs] replaced ToString MacroAssembler Stub with CodeStubAssembler builtin

src/arm64/code-stubs-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/code-stubs.h"
 #include "src/api-arguments.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 2655 matching lines @@
     // Compute the entry point of the rewritten stub.
     __ Add(stub_entry, x0, Code::kHeaderSize - kHeapObjectTag);
     // Restore caller-saved registers.
     __ Pop(lr, x0, x1);
   }
 
   // Tail-call to the new stub.
   __ Jump(stub_entry);
 }
 
-void ToStringStub::Generate(MacroAssembler* masm) {
-  // The ToString stub takes one argument in x0.
-  Label is_number;
-  __ JumpIfSmi(x0, &is_number);
-
-  Label not_string;
-  __ JumpIfObjectType(x0, x1, x1, FIRST_NONSTRING_TYPE, &not_string, hs);
-  // x0: receiver
-  // x1: receiver instance type
-  __ Ret();
-  __ Bind(&not_string);
-
-  Label not_heap_number;
-  __ Cmp(x1, HEAP_NUMBER_TYPE);
-  __ B(ne, &not_heap_number);
-  __ Bind(&is_number);
-  NumberToStringStub stub(isolate());
-  __ TailCallStub(&stub);
-  __ Bind(&not_heap_number);
-
-  Label not_oddball;
-  __ Cmp(x1, ODDBALL_TYPE);
-  __ B(ne, &not_oddball);
-  __ Ldr(x0, FieldMemOperand(x0, Oddball::kToStringOffset));
-  __ Ret();
-  __ Bind(&not_oddball);
-
-  __ Push(x0);  // Push argument.
-  __ TailCallRuntime(Runtime::kToString);
-}
-
 
 void StringHelper::GenerateFlatOneByteStringEquals(
     MacroAssembler* masm, Register left, Register right, Register scratch1,
     Register scratch2, Register scratch3) {
   DCHECK(!AreAliased(left, right, scratch1, scratch2, scratch3));
   Register result = x0;
   Register left_length = scratch1;
   Register right_length = scratch2;
 
   // Compare lengths. If lengths differ, strings can't be equal. Lengths are
@@ skipping 2557 matching lines @@
                            kStackUnwindSpace, NULL, spill_offset,
                            return_value_operand, NULL);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM64