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_lower_samplers.c

@@ -160,7 +160,7 @@ lower_impl(nir_function_impl *impl, const struct gl_shader_program *shader_progr
    nir_builder_init(&b, impl);
 
    nir_foreach_block(block, impl) {
-      nir_foreach_instr(block, instr) {
+      nir_foreach_instr(instr, block) {
          if (instr->type == nir_instr_type_tex)
             lower_sampler(nir_instr_as_tex(instr), shader_program, stage, &b);
       }