i965: Don't try to fall back when creating unrecognized program targets.
i965: Don't try to fall back when creating unrecognized program targets.

If brwNewProgram is asked to create a program for an unrecognized
target, don't bother falling back on _mesa_new_program().  That just
hides bugs.

Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>

v2: Use assert() rather than _mesa_problem().

Reviewed-by: Kenneth Graunke <bd2562f754ec92342f93f61c25d731e290a2ffa8@whitecape.org>
Reviewed-by: Chad Versace <a557f7f75bf28dc19ac99107f5cc7cd6b3fbdb1a@linux.intel.com>

dellis1972/glsl-optimizer,zz85/glsl-optimizer,tokyovigilante/glsl-optimizer,bkaradzic/glsl-optimizer,dellis1972/glsl-optimizer,bkaradzic/glsl-optimizer,zeux/glsl-optimizer,benaadams/glsl-optimizer,djreep81/glsl-optimizer,wolf96/glsl-optimizer,benaadams/glsl-optimizer,mapbox/glsl-optimizer,djreep81/glsl-optimizer,benaadams/glsl-optimizer,zeux/glsl-optimizer,wolf96/glsl-optimizer,tokyovigilante/glsl-optimizer,mcanthony/glsl-optimizer,metora/MesaGLSLCompiler,jbarczak/glsl-optimizer,mapbox/glsl-optimizer,mapbox/glsl-optimizer,bkaradzic/glsl-optimizer,dellis1972/glsl-optimizer,mapbox/glsl-optimizer,mapbox/glsl-optimizer,jbarczak/glsl-optimizer,wolf96/glsl-optimizer,benaadams/glsl-optimizer,tokyovigilante/glsl-optimizer,wolf96/glsl-optimizer,djreep81/glsl-optimizer,mcanthony/glsl-optimizer,wolf96/glsl-optimizer,zz85/glsl-optimizer,mcanthony/glsl-optimizer,jbarczak/glsl-optimizer,zz85/glsl-optimizer,mcanthony/glsl-optimizer,benaadams/glsl-optimizer,djreep81/glsl-optimizer,jbarczak/glsl-optimizer,zeux/glsl-optimizer,metora/MesaGLSLCompiler,tokyovigilante/glsl-optimizer,bkaradzic/glsl-optimizer,benaadams/glsl-optimizer,dellis1972/glsl-optimizer,zz85/glsl-optimizer,zz85/glsl-optimizer,metora/MesaGLSLCompiler,zeux/glsl-optimizer,tokyovigilante/glsl-optimizer,zeux/glsl-optimizer,bkaradzic/glsl-optimizer,djreep81/glsl-optimizer,mcanthony/glsl-optimizer,jbarczak/glsl-optimizer,zz85/glsl-optimizer,dellis1972/glsl-optimizer