For macOS platform, disable vsync for -metal backend to not slow down the VM interpreter loop.
For macOS platform, disable vsync for -metal backend to not slow down the VM interpreter loop.

NOTE THAT we now have sporadic segfaults as with the -core-graphics backend. There is a @synchronized missing somewhere. I suspect something around input events bc. the crashes always happen after a mouse click...

timfel/squeakvm,timfel/squeakvm,timfel/squeakvm,timfel/squeakvm,timfel/squeakvm,timfel/squeakvm,timfel/squeakvm,timfel/squeakvm