left shift count >= width of type
With optimization on, cartridge_size will result in garbage/undefined
behavior and break loading of games not found in the database, because
the size will always be > 131072 and wrongly identify cartridge_type as
CARTRIDGE_TYPE_SUPERCART_LARGE
Fixes loading of good ROM dumps where previously only their overdumps
would load (Tower Toppler, Realsports Baseball, Water Ski, etc)
Patch credits to Joseph Zatarski of ##Atari on Freenode IRC
