aux/draw: Check for preferred IR to take nir-to-tgsi path in draw module
When a vertex program is translated to nir, it uses nir_to_tgsi_compile_options for drivers with only nir-to-tgsi based NIR support. But this compile option might not be the same as the NIR compile option from llvmpipe, hence when the nir shader is bound to the draw module, it hits an assertion in do_alu_action() when encounters nir_op_fdot3.
With this patch, draw will take the nir-to-tgsi path if preferred IR from the driver is TGSI.
Fixes assert running Maya on SVGA device.