Mesa (master): glsl: Check that 'centroid in' does not occur in vertex shader

[Chad Versace]

Module: Mesa
Branch: master
Commit: 1eb0f17fa4aa548779cb7d8ffbd86de3523d6796
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=1eb0f17fa4aa548779cb7d8ffbd86de3523d6796

Author: Chad Versace <chad.versace at intel.com>
Date:   Tue Jan 11 18:24:17 2011 -0800

glsl: Check that 'centroid in' does not occur in vertex shader

The check is performed only in GLSL versions >= 1.30.