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

src/full-codegen/arm64/full-codegen-arm64.cc

Index: src/full-codegen/arm64/full-codegen-arm64.cc
diff --git a/src/full-codegen/arm64/full-codegen-arm64.cc b/src/full-codegen/arm64/full-codegen-arm64.cc
index 55ac3f5f9185b52e23d46e75460d66546e2aa0db..0dc3ffd30bcd540896a86f3b1e5bed4aa332aa97 100644
--- a/src/full-codegen/arm64/full-codegen-arm64.cc
+++ b/src/full-codegen/arm64/full-codegen-arm64.cc
@@ -3689,6 +3689,38 @@ void FullCodeGenerator::EmitNumberToString(CallRuntime* expr) {
 }
 
 
+void FullCodeGenerator::EmitToString(CallRuntime* expr) {
+  ZoneList<Expression*>* args = expr->arguments();
+  DCHECK_EQ(1, args->length());
+
+  // Load the argument into x0 and convert it.
+  VisitForAccumulatorValue(args->at(0));
+
+  ToStringStub stub(isolate());
+  __ CallStub(&stub);
+  context()->Plug(x0);
+}
+
+
+void FullCodeGenerator::EmitToName(CallRuntime* expr) {
+  ZoneList<Expression*>* args = expr->arguments();
+  DCHECK_EQ(1, args->length());
+
+  // Load the argument into x0 and convert it.
+  VisitForAccumulatorValue(args->at(0));
+
+  Label convert, done_convert;
+  __ JumpIfSmi(x0, &convert);
+  STATIC_ASSERT(FIRST_NAME_TYPE == FIRST_TYPE);
+  __ JumpIfObjectType(x0, x1, x1, LAST_NAME_TYPE, &done_convert, ls);
+  __ Bind(&convert);
+  ToStringStub stub(isolate());
+  __ CallStub(&stub);
+  __ Bind(&done_convert);
+  context()->Plug(x0);
+}
+
+
 void FullCodeGenerator::EmitToObject(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK_EQ(1, args->length());