[stubs] StringToNumberStub --> StringToNumber builtin.

src/mips64/builtins-mips64.cc

Index: src/mips64/builtins-mips64.cc
diff --git a/src/mips64/builtins-mips64.cc b/src/mips64/builtins-mips64.cc
index c4ae7edee79b0a837e5d4915345b3246fb09a0c4..3c31bf10a5ee71e062a6e6584abbe3ca4d71f658 100644
--- a/src/mips64/builtins-mips64.cc
+++ b/src/mips64/builtins-mips64.cc
@@ -2751,6 +2751,24 @@ void Builtins::Generate_AllocateInOldSpace(MacroAssembler* masm) {
   __ TailCallRuntime(Runtime::kAllocateInTargetSpace);
 }
 
+// static
+void Builtins::Generate_StringToNumber(MacroAssembler* masm) {
+  // The StringToNumber stub takes on argument in a0.
+  __ AssertString(a0);
+
+  // Check if string has a cached array index.
+  Label runtime;
+  __ lwu(a2, FieldMemOperand(a0, String::kHashFieldOffset));
+  __ And(at, a2, Operand(String::kContainsCachedArrayIndexMask));
+  __ Branch(&runtime, ne, at, Operand(zero_reg));
+  __ IndexFromHash(a2, v0);
+  __ Ret();
+
+  __ bind(&runtime);
+  __ Push(a0);  // Push argument.
+  __ TailCallRuntime(Runtime::kStringToNumber);
+}
+
 void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   // State setup as expected by MacroAssembler::InvokePrologue.
   // ----------- S t a t e -------------