[tlbuild] -funsigned-char is not portable

[Vladimir Volovich]

Hi!

i'm getting this error:

/bin/bash ./libtool --tag=CC   --mode=link xlc -funsigned-char -O2 -qmaxmem=262144 -qarch=com -qlanglvl=extended -qcpluscmt   -o bibtex8 bibtex-1.o bibtex-2.o bibtex-3.o bibtex-4.o bibtex.o utils.o /usr/local/vvv/src/source/Work/texk/kpathsea/libkpathsea.la        
libtool: link: xlc -funsigned-char -O2 -qmaxmem=262144 -qarch=com -qlanglvl=extended -qcpluscmt -o bibtex8 bibtex-1.o bibtex-2.o bibtex-3.o bibtex-4.o bibtex.o utils.o  /usr/local/vvv/src/source/Work/texk/kpathsea/.libs/libkpathsea.a
ld: 0706-005 Cannot find or open file: unsigned-char
        ld:fopen(): No such file or directory
make[3]: *** [bibtex8] Error 255
make[3]: Leaving directory `/usr/local/vvv/src/source/Work/texk/bibtex8'

the proper flag for this compiler is -qchars=unsigned which should be
tested via configure (if there is such a test), or -funsigned-char
should be removed.

Best,
v.