configure: add Haiku NASM support
configure: add Haiku NASM support

And print an error on attempts to use ASM on an unrecognized system as
NASM would very likely produce borked files anyway.
(erroring out can still be avoided with --disable-asm)

xbmc/libass,ShiftMediaProject/libass,astiob/libass,xbmc/libass,Akemi/libass,astiob/libass,libass/libass,MrSmile/libass,Akemi/libass,ShiftMediaProject/libass,MrSmile/libass,Akemi/libass,libass/libass