[stubs] replaced ToString MacroAssembler Stub with CodeStubAssembler builtin

src/mips/code-stubs-mips.cc

Index: src/mips/code-stubs-mips.cc
diff --git a/src/mips/code-stubs-mips.cc b/src/mips/code-stubs-mips.cc
index 68cb356d002b781f73056230ec664c2f887d9c91..f33a2b071377e9f5ab5229458811ad5f8c233867 100644
--- a/src/mips/code-stubs-mips.cc
+++ b/src/mips/code-stubs-mips.cc
@@ -2491,38 +2491,6 @@ void SubStringStub::Generate(MacroAssembler* masm) {
 }
 
 
-void ToStringStub::Generate(MacroAssembler* masm) {
-  // The ToString stub takes on argument in a0.
-  Label is_number;
-  __ JumpIfSmi(a0, &is_number);
-
-  Label not_string;
-  __ GetObjectType(a0, a1, a1);
-  // a0: receiver
-  // a1: receiver instance type
-  __ Branch(&not_string, ge, a1, Operand(FIRST_NONSTRING_TYPE));
-  __ Ret(USE_DELAY_SLOT);
-  __ mov(v0, a0);
-  __ bind(&not_string);
-
-  Label not_heap_number;
-  __ Branch(&not_heap_number, ne, a1, Operand(HEAP_NUMBER_TYPE));
-  __ bind(&is_number);
-  NumberToStringStub stub(isolate());
-  __ TailCallStub(&stub);
-  __ bind(&not_heap_number);
-
-  Label not_oddball;
-  __ Branch(&not_oddball, ne, a1, Operand(ODDBALL_TYPE));
-  __ Ret(USE_DELAY_SLOT);
-  __ lw(v0, FieldMemOperand(a0, Oddball::kToStringOffset));
-  __ bind(&not_oddball);
-
-  __ push(a0);  // Push argument.
-  __ TailCallRuntime(Runtime::kToString);
-}
-
-
 void StringHelper::GenerateFlatOneByteStringEquals(
     MacroAssembler* masm, Register left, Register right, Register scratch1,
     Register scratch2, Register scratch3) {