Add rbconfig/sizeof to stdlib
Add rbconfig/sizeof to stdlib

Just for libs requiring it, not intended as reliable.
Mogztter/opal,Mogztter/opal,opal/opal,iliabylich/opal,opal/opal,Mogztter/opal,Mogztter/opal,kachick/opal,opal/opal,iliabylich/opal,opal/opal,kachick/opal,kachick/opal,kachick/opal,iliabylich/opal