agx: Implement unary math ops
Implement nir_op_bitfield_reverse, nir_op_bit_count, and
nir_op_ufind_msb. These map to native instructions. With appropriate
integer render target and multiple render target support, passes:
dEQP-GLES31.functional.shaders.builtin_functions.integer.bitfieldreverse.*vertex
dEQP-GLES31.functional.shaders.builtin_functions.integer.bitfieldreverse.*fragment
dEQP-GLES31.functional.shaders.builtin_functions.integer.bitcount.*vertex
dEQP-GLES31.functional.shaders.builtin_functions.integer.bitcount.*fragment
dEQP-GLES31.functional.shaders.builtin_functions.integer.findLSB.*vertex
dEQP-GLES31.functional.shaders.builtin_functions.integer.findLSB.*fragment
dEQP-GLES31.functional.shaders.builtin_functions.integer.findMSB.*vertex
dEQP-GLES31.functional.shaders.builtin_functions.integer.findMSB.*fragment
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19590>