[stubs] Introduce ToIntegerStub and unify the handling of %_ToInteger.

src/full-codegen/mips/full-codegen-mips.cc

Index: src/full-codegen/mips/full-codegen-mips.cc
diff --git a/src/full-codegen/mips/full-codegen-mips.cc b/src/full-codegen/mips/full-codegen-mips.cc
index 68bf6aa815dee288d907d892dda1308209d53321..bde7f6eb468070e28ba8976fff438b6f7c5813a2 100644
--- a/src/full-codegen/mips/full-codegen-mips.cc
+++ b/src/full-codegen/mips/full-codegen-mips.cc
@@ -3127,23 +3127,6 @@ void FullCodeGenerator::EmitTwoByteSeqStringSetChar(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitToInteger(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK_EQ(1, args->length());
-
-  // Load the argument into v0 and convert it.
-  VisitForAccumulatorValue(args->at(0));
-
-  // Convert the object to an integer.
-  Label done_convert;
-  __ JumpIfSmi(v0, &done_convert);
-  __ Push(v0);
-  __ CallRuntime(Runtime::kToInteger);
-  __ bind(&done_convert);
-  context()->Plug(v0);
-}
-
-
 void FullCodeGenerator::EmitStringCharFromCode(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);