Makefile compile issues on OSX

[kodefoo]

I could not run the Makefile on a Mac OSX 10.15.5 system using gcc.

I received the following error.

gcc -W -Wall -std=c99 -O2 -s -m64 -DOSX -o pp64.app pp.c mpz_int128.h
clang: error: cannot specify -o when generating multiple output files
make: *** [pp64.app] Error 1

I was able to fix the issue by removing the header file from the Makefile rules.

pp64.app: pp.c
$(CC_OSX64) $(CFLAGS_OSX64) -o $@ $^