Turn ToNumberStub into a PlatformCodeStub again.

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.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 3815 matching lines @@
   StringCharAtGenerator generator(input_string, from, result_length, x0,
                                   &runtime, &runtime, &runtime,
                                   STRING_INDEX_IS_NUMBER, RECEIVER_IS_STRING);
   generator.GenerateFast(masm);
   __ Drop(3);
   __ Ret();
   generator.SkipSlow(masm, &runtime);
 }
 
 
+void ToNumberStub::Generate(MacroAssembler* masm) {
+  // The ToNumber stub takes one argument in x0.
+  Label check_heap_number, call_builtin;
+  __ JumpIfNotSmi(x0, &check_heap_number);
+  __ Ret();
+
+  __ bind(&check_heap_number);
+  __ JumpIfNotHeapNumber(x0, &call_builtin);
+  __ Ret();
+
+  __ bind(&call_builtin);
+  __ push(x0);
+  __ InvokeBuiltin(Builtins::TO_NUMBER, JUMP_FUNCTION);
+}
+
+
 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
   // smis, and don't need to be untagged.
@@ skipping 1255 matching lines @@
                               MemOperand(fp, 6 * kPointerSize),
                               NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64