nir/inline: Make the rewrite_param_derefs helper work on instructions
nir/inline: Make the rewrite_param_derefs helper work on instructions

Now that we have the better nir_foreach_block macro, there's no reason to
use the archaic block version for everything.

Reviewed-by: Connor Abbott <71178acffcc112b21e5858656e5751f5e4aa9364@gmail.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler