Turn ToNumberStub into a PlatformCodeStub again.

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index a5a34a4b9771b643d2d4b46e0faa72cf57356444..a0e7e4a33ecb899bed91522970b315308c1a3fe5 100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -3187,6 +3187,24 @@ void SubStringStub::Generate(MacroAssembler* masm) {
 }
 
 
+void ToNumberStub::Generate(MacroAssembler* masm) {
+  // The ToNumber stub takes one argument in r0.
+  Label check_heap_number, call_builtin;
+  __ JumpIfNotSmi(r0, &check_heap_number);
+  __ Ret();
+
+  __ bind(&check_heap_number);
+  __ ldr(r1, FieldMemOperand(r0, HeapObject::kMapOffset));
+  __ CompareRoot(r1, Heap::kHeapNumberMapRootIndex);
+  __ b(ne, &call_builtin);
+  __ Ret();
+
+  __ bind(&call_builtin);
+  __ push(r0);
+  __ InvokeBuiltin(Builtins::TO_NUMBER, JUMP_FUNCTION);
+}
+
+
 void StringHelper::GenerateFlatOneByteStringEquals(
     MacroAssembler* masm, Register left, Register right, Register scratch1,
     Register scratch2, Register scratch3) {