[Chicken-hackers] build fails on OS X Intel due to apply-hack

[Zbigniew]

... because the apply-hack.x86.s generates C_do_apply_hack without the
underscore prefix required by OS X.  I manually compiled apply-hack.s
by running libtool with this extra define:
-DC_do_apply_hack=_C_do_apply_hack

and it works perfectly.  However I cannot figure out how to update the
configure script appropriately or even solve it in the general case.