2013Q2 MesaLib and pbulk

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

Hello,
another pbulk issue in the 2013Q2 branch: MesaLib doesn't build 
on 5.1 because it doens't find dri2proto, as seen here:
http://nyftp.netbsd.org/pub/pkgsrc/packages/reports/2013Q2/NetBSD-5.1-x86_64/20130828.0632/MesaLib-7.11.2nb2/configure.log

It seems that the build-in dri2proto is not found by pkg-config, although
it's there:
/usr/X11R7/lib/pkgconfig/dri2proto.pc.

On 6.0 dri2proto.pc is at the same place and is properly found.

2 differences between 5.1 and 6.0:
- on 5.1 the built-in dri2proto is 2.1, on 6.0 it's 2.6.
  It shouldn't matter as configure claims to need >= 2.1
- on 6.0 it uses the built-in glproto, on 5.1 is uses the pkgsrc one.
  I don't know if this can affect pkg-config's search path ...

Any idea ?

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--