intel/compiler: Add missing breaks

Reviewed-by: Caio Oliveira <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34014>

src/intel/compiler/brw_opt_algebraic.cpp

@@ -548,6 +548,7 @@ brw_opt_algebraic(brw_shader &s)
                default:
                   break;
                }
+               break;
             default:
                break;
             }

src/intel/compiler/elk/elk_fs.cpp

@@ -2437,6 +2437,7 @@ elk_fs_visitor::opt_algebraic()
                default:
                   break;
                }
+               break;
             default:
                break;
             }