intel/compiler: Re-prefix non-logical surface opcodes with VEC4

The scalar back-end uses SHADER_OPCODE_SEND for all surface messages so
we no longer need the non-logical opcodes there.  Prefix them VEC4 so
it's clear that they're only used by the vec4 back-end.

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>

src/intel/compiler/brw_vec4_copy_propagation.cpp

@@ -190,7 +190,7 @@ try_constant_propagate(const struct gen_device_info *devinfo,
       inst->src[arg] = value;
       return true;
 
-   case SHADER_OPCODE_UNTYPED_ATOMIC:
+   case VEC4_OPCODE_UNTYPED_ATOMIC:
       if (arg == 1) {
          inst->src[arg] = value;
          return true;