[builtins] Migrate StringToNumber to TurboFan builtin.

src/builtins/x64/builtins-x64.cc

Index: src/builtins/x64/builtins-x64.cc
diff --git a/src/builtins/x64/builtins-x64.cc b/src/builtins/x64/builtins-x64.cc
index d67583730d9536d6bb9fce43bc6b44a344b0d6c4..d4ae1c2222adf7fb1b34b4439668f7ed55d47a72 100644
--- a/src/builtins/x64/builtins-x64.cc
+++ b/src/builtins/x64/builtins-x64.cc
@@ -2128,31 +2128,6 @@ void Builtins::Generate_Abort(MacroAssembler* masm) {
   __ TailCallRuntime(Runtime::kAbort);
 }
 
-void Builtins::Generate_StringToNumber(MacroAssembler* masm) {
-  // The StringToNumber stub takes one argument in rax.
-  __ AssertString(rax);
-
-  // Check if string has a cached array index.
-  Label runtime;
-  __ testl(FieldOperand(rax, String::kHashFieldOffset),
-           Immediate(String::kContainsCachedArrayIndexMask));
-  __ j(not_zero, &runtime, Label::kNear);
-  __ movl(rax, FieldOperand(rax, String::kHashFieldOffset));
-  __ IndexFromHash(rax, rax);
-  __ Ret();
-
-  __ bind(&runtime);
-  {
-    FrameScope frame(masm, StackFrame::INTERNAL);
-    // Push argument.
-    __ Push(rax);
-    // We cannot use a tail call here because this builtin can also be called
-    // from wasm.
-    __ CallRuntime(Runtime::kStringToNumber);
-  }
-  __ Ret();
-}
-
 // static
 void Builtins::Generate_ToNumber(MacroAssembler* masm) {
   // The ToNumber stub takes one argument in rax.