i965/vs: Pass the current set of clip planes through run() and run_vs()

i965/vs: Pass the current set of clip planes through run() and run_vs()

Previously, these were pulled out of the GL context conditionally based on
whether we were running ff/ARB or a GLSL program.  Now, we just pass them
in so that the visitor doesn't have to grab them itself.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Chris Forbes <chrisf@ijw.co.nz>