Tessellation control shaders are optional, but evaluation shaders will
always be present when using tessellation. However, we'll always enable
the TCS (HS) hardware stage when using tessellation - we'll just create
a program on the fly.
That program, however, won't have a gl_program or gl_shader_program.
So we shouldn't check brw->tess_ctrl_program or
shader_prog->_LinkedShaders[MESA_SHADER_TESS_CTRL] - if we want to know
whether tessellation is enabled, we should look for a TES.
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
a122af696c