Mesa (master): glsl: Check that interpolation qualifiers do not precede ' varying'

[Chad Versace]

Module: Mesa
Branch: master
Commit: 605aacc67d73db0926e0046a90a07fcd93a2d613
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=605aacc67d73db0926e0046a90a07fcd93a2d613

Author: Chad Versace <chad.versace at intel.com>
Date:   Tue Jan 11 17:21:18 2011 -0800

glsl: Check that interpolation qualifiers do not precede 'varying'

... and 'centroid varying'. The check is performed only in GLSL
versions >= 1.30.