Add a MathFloor stub generated with TurboFan

src/runtime/runtime-collections.cc

Index: src/runtime/runtime-collections.cc
diff --git a/src/runtime/runtime-collections.cc b/src/runtime/runtime-collections.cc
index e5f3ba1cfb71bd76badc67e2295951537ef2dd39..3a7d02cf35f76dc19816ad8a0fa18d988c61fbd2 100644
--- a/src/runtime/runtime-collections.cc
+++ b/src/runtime/runtime-collections.cc
@@ -27,26 +27,6 @@ RUNTIME_FUNCTION(Runtime_TheHole) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_FixedArrayGet) {
-  SealHandleScope shs(isolate);
-  DCHECK(args.length() == 2);
-  CONVERT_ARG_CHECKED(FixedArray, object, 0);
-  CONVERT_SMI_ARG_CHECKED(index, 1);
-  return object->get(index);
-}
-
-
-RUNTIME_FUNCTION(Runtime_FixedArraySet) {
-  SealHandleScope shs(isolate);
-  DCHECK(args.length() == 3);
-  CONVERT_ARG_CHECKED(FixedArray, object, 0);
-  CONVERT_SMI_ARG_CHECKED(index, 1);
-  CONVERT_ARG_CHECKED(Object, value, 2);
-  object->set(index, value);
-  return isolate->heap()->undefined_value();
-}
-
-
 RUNTIME_FUNCTION(Runtime_JSCollectionGetTable) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 1);