nir: Add a bool to int32 lowering pass

We also enable it in all of the NIR drivers.

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Tested-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

src/gallium/drivers/vc4/vc4_program.c

@@ -2385,6 +2385,8 @@ vc4_shader_ntq(struct vc4_context *vc4, enum qstage stage,
 
         vc4_optimize_nir(c->s);
 
+        NIR_PASS_V(c->s, nir_lower_bool_to_int32);
+
         NIR_PASS_V(c->s, nir_convert_from_ssa, true);
 
         if (vc4_debug & VC4_DEBUG_SHADERDB) {