Fix a regression in FFI (can't pass single float on the stack)
Fix a regression in FFI (can't pass single float on the stack)

The macros storeSingleFloatAtPointerfrom and fetchSingleFloatAtPointerinto are used with double precision values.
We cannot naively memcpy without first copying into a single float...

peteruhnak/pharo-vm,OpenSmalltalk/vm,bencoman/pharo-vm,OpenSmalltalk/vm,bencoman/pharo-vm,OpenSmalltalk/vm,peteruhnak/pharo-vm,timfel/squeakvm,peteruhnak/pharo-vm,peteruhnak/pharo-vm,peteruhnak/pharo-vm,timfel/squeakvm,peteruhnak/pharo-vm,timfel/squeakvm,bencoman/pharo-vm,bencoman/pharo-vm,bencoman/pharo-vm,OpenSmalltalk/vm,bencoman/pharo-vm,OpenSmalltalk/vm,OpenSmalltalk/vm,peteruhnak/pharo-vm,OpenSmalltalk/vm,peteruhnak/pharo-vm,bencoman/pharo-vm,timfel/squeakvm,timfel/squeakvm,OpenSmalltalk/vm,timfel/squeakvm,timfel/squeakvm,timfel/squeakvm,bencoman/pharo-vm,bencoman/pharo-vm