Since commit 2881b123, we have used 0/~0 for representing booleans on all
gens. However, we still had a bunch of places in the visitor code where we
were still referring to ctx->Const.UniformBooleanTrue. Since this is
always ~0, we can just remove them.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>