[runtime] Add %ToString and %_ToString and remove the TO_STRING builtin.

src/full-codegen/mips64/full-codegen-mips64.cc

Index: src/full-codegen/mips64/full-codegen-mips64.cc
diff --git a/src/full-codegen/mips64/full-codegen-mips64.cc b/src/full-codegen/mips64/full-codegen-mips64.cc
index 10e4580411ee9ae4802476306556a17d82516131..048e01c15933b5ce9780990974d3aafa465f3ac6 100644
--- a/src/full-codegen/mips64/full-codegen-mips64.cc
+++ b/src/full-codegen/mips64/full-codegen-mips64.cc
@@ -3993,6 +3993,41 @@ void FullCodeGenerator::EmitNumberToString(CallRuntime* expr) {
 }
 
 
+void FullCodeGenerator::EmitToString(CallRuntime* expr) {
+  ZoneList<Expression*>* args = expr->arguments();
+  DCHECK_EQ(1, args->length());
+
+  // Load the argument into a0 and convert it.
+  VisitForAccumulatorValue(args->at(0));
+  __ mov(a0, result_register());
+
+  ToStringStub stub(isolate());
+  __ CallStub(&stub);
+  context()->Plug(v0);
+}
+
+
+void FullCodeGenerator::EmitToName(CallRuntime* expr) {
+  ZoneList<Expression*>* args = expr->arguments();
+  DCHECK_EQ(1, args->length());
+
+  // Load the argument into v0 and convert it.
+  VisitForAccumulatorValue(args->at(0));
+
+  Label convert, done_convert;
+  __ JumpIfSmi(v0, &convert);
+  STATIC_ASSERT(FIRST_NAME_TYPE == FIRST_TYPE);
+  __ GetObjectType(v0, a1, a1);
+  __ Branch(&done_convert, le, a1, Operand(LAST_NAME_TYPE));
+  __ bind(&convert);
+  ToStringStub stub(isolate());
+  __ mov(a0, v0);
+  __ CallStub(&stub);
+  __ bind(&done_convert);
+  context()->Plug(v0);
+}
+
+
 void FullCodeGenerator::EmitToObject(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK_EQ(1, args->length());