[runtime] Implement %_ToLength via ToLengthStub.

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 ceb0926eb73116fdc3b4e9c6fc4e503a9cd9db55..020d385161e42a46e6b50d41c4f4ba697e580508 100644
--- a/src/full-codegen/mips64/full-codegen-mips64.cc
+++ b/src/full-codegen/mips64/full-codegen-mips64.cc
@@ -3814,6 +3814,20 @@ void FullCodeGenerator::EmitNumberToString(CallRuntime* expr) {
 }
 
 
+void FullCodeGenerator::EmitToLength(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());
+
+  ToLengthStub stub(isolate());
+  __ CallStub(&stub);
+  context()->Plug(v0);
+}
+
+
 void FullCodeGenerator::EmitToString(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK_EQ(1, args->length());