[tlbuild] xetex bugfix

[Taco Hoekwater]

Peter Breitenlohner wrote:
> 
> theoretically this should work, but in fact it does not quite. Due to an
> unsolved dependency problem you have to repeat 'make xetex' two or three
> times until nothing is rebuilt.  I'd love to understand the cause of this
> (until now mysterious) behaviour.

For luatex, it seems this is because luatex.p depends on libluatex.a,
but even if there is a change in one of the C files, the archive has
not changed yet at the time it is decided whether the pascal conversion
needs to be run.

> However, as Karl has said there is no rush to rebuild the xetex binaries.

Because of this, I will make use of the opportunity: metapost 1.204 and
luatex 0.40.6 are also coming in, in an hour or so.

Best wishes,
Taco