[tlbuild] xetex and xdvipdfmx: explicit dependency on external libfreetype and libz

[Karl Berry]

     PB> BTW: in the TL2008 build (Master/bin/*/{xetex,xdvipdfmx}) the xetex
     PB> for i386-openbsd and the xdvipdfmx for i386-openbsd, i386-freebsd,
     PB> amd64-freebsd, x86_+64-linux, and powerpc-linux all depend os
     PB> system freetype, expat and z libraries.

    these are indirect dependencies, as explained above. e.g. you should
    not be seeing libexpat inside the xetex binary. it is induced by
    fontconfig.

Peter doesn't mention i386-linux.  As far as I can tell the xetex binary
I made for i386-linux (on Debian Sarge) in 2008 does have explicit
dependencies on 
	linux-gate.so.1 =>  (0xb7f99000)
	libfontconfig.so.1 => /usr/lib/libfontconfig.so.1 (0x0091e000)
	libm.so.6 => /lib/libm.so.6 (0x005d9000)
	libc.so.6 => /lib/libc.so.6 (0x00493000)
	libfreetype.so.6 => /usr/lib/libfreetype.so.6 (0x00864000)
	libexpat.so.0 => /lib/libexpat.so.0 (0x00841000)
	/lib/ld-linux.so.2 (0x00470000)

(But not libz, which was statically linked.  From what I gather of
previous discussion, it's not easy to change libz back to static in
xetex under the new regime.)

    so i'm trying to avoid unnecessary direct dependencies on system
    libfreetype and libz.

If we can make the dependencies indirect, surely that is all to the
good.  But I think the evidence is that it is not crucial if we don't.
At least I never saw reams of (or any) complaints from users about how
their xetex wouldn't run.

I will try your change on i386-linux and see what results.

THanks,
karl