nir: Rename nir_intrinsic_barrier to control_barrier

This is a more explicit name now that we don't want it to be doing any
memory barrier stuff for us.

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3307>

src/compiler/glsl/glsl_to_nir.cpp

@@ -2714,7 +2714,7 @@ nir_visitor::visit(ir_barrier *)
    }
 
    nir_intrinsic_instr *instr =
-      nir_intrinsic_instr_create(this->shader, nir_intrinsic_barrier);
+      nir_intrinsic_instr_create(this->shader, nir_intrinsic_control_barrier);
    nir_builder_instr_insert(&b, &instr->instr);
 }