nir/lower_phis_to_scalar: fixup for new foreach_block()
nir/lower_phis_to_scalar: fixup for new foreach_block()

Reviewed-by: Jason Ekstrand <68c46a606457643eab92053c1c05574abb26f861@jlekstrand.net>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler