Hostile mobs spawning on glass

With recent changes to glass (and stained glass) from non-solid to solid to (almost) non-solid again, mobs now spawn on it. May be related to MC-139394.

 

Edit: Further tests showed monsters also spawning on most transparent blocks, as long as they provide a full surface. Tested Glowstone and Sea Lanterns in the Nether, since light doesn't affect most Nether monsters.