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_sweep.c

@@ -63,7 +63,7 @@ sweep_block(nir_shader *nir, nir_block *block)
 {
    ralloc_steal(nir, block);
 
-   nir_foreach_instr(block, instr) {
+   nir_foreach_instr(instr, block) {
       ralloc_steal(nir, instr);
 
       nir_foreach_src(instr, sweep_src_indirect, nir);