mg 1.3x has been successfully built on NeXT Mach 3.3, but only after
several painful experiments to find compiler options that would work
around NeXT's horrid bugs.  The NeXT has always been seriously
brain-damaged because of errors in the C header files and libraries.

I found that

	./configure
	make CC='cc -DINT_MAX=0x7fffffff'
	ar d lib/libmg.a gmalloc.o
	ranlib -s lib/libmg.a
	make CC='cc -DINT_MAX=0x7fffffff'

seems to do the trick.

The symbol INT_MAX is defined only in the Standard C environment (cc
-ansi), but in that environment, <ctype.h> expands isascii() to a
function instead of a macro, and that function is absent from the
system libraries, sigh...

Deletion of the gmalloc.o member of the libmg.a library is necessary
to prevent fatal linker duplicate-symbol conflicts.