nir: Switch the arguments to nir_foreach_instr

This matches the "foreach x in container" pattern found in many other
programming languages.  Generated by the following regular expression:

s/nir_foreach_instr(\([^,]*\),\s*\([^,]*\))/nir_foreach_instr(\2, \1)/

and similar expressions for nir_foreach_instr_safe etc.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

src/compiler/nir/nir_opt_copy_propagate.c

@@ -246,7 +246,7 @@ nir_copy_prop_impl(nir_function_impl *impl)
    bool progress = false;
 
    nir_foreach_block(block, impl) {
-      nir_foreach_instr(block, instr) {
+      nir_foreach_instr(instr, block) {
          if (copy_prop_instr(instr))
             progress = true;
       }