gfx-rs/gfx-rs — pull request #481 by serpis (2014-12-21 14:10:50+00:00)
Title: Fix built-in filter on buggy drivers.

OS X v10.7 GMA 950 driver reports gl_InstanceID on location != -1, even should built-ins should always be there.
Need to work around this in the gfx-rs...