broadcom/compiler: add lowering pass to scalarize non 32-bit general load/store

V3D hardware doesn't support vector access for general TMU load/store
operations like the ones we use for UBO and SSBO, so we need to split
these to scalar operations.

It should be noted that we also have a vectorization pass (which runs
later, during optimization), that may reconstruct some of these into
32-bit operations when possible (i.e. when the resulting operation
is 32-bit aligned).

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14648>

src/broadcom/compiler/v3d_compiler.h

@@ -1109,6 +1109,7 @@ void v3d_nir_lower_robust_buffer_access(nir_shader *shader, struct v3d_compile *
 void v3d_nir_lower_scratch(nir_shader *s);
 void v3d_nir_lower_txf_ms(nir_shader *s, struct v3d_compile *c);
 void v3d_nir_lower_image_load_store(nir_shader *s);
+void v3d_nir_lower_load_store_bitsize(nir_shader *s, struct v3d_compile *c);
 
 void v3d33_vir_vpm_read_setup(struct v3d_compile *c, int num_components);
 void v3d33_vir_vpm_write_setup(struct v3d_compile *c);