zlib: Annotate fallthrough case

include/boost/beast/_experimental/unit_test/match.hpp

@@ -113,7 +113,6 @@ selector::operator()(suite_info const& s)
 
     case all:
     default:
-        // fall through
         break;
     };
 

include/boost/beast/zlib/detail/inflate_stream.ipp

@@ -138,7 +138,7 @@ doWrite(z_params& zs, Flush flush, error_code& ec)
         case TYPE:
             if(flush == Flush::block || flush == Flush::trees)
                 return done();
-            // fall through
+            BOOST_FALLTHROUGH;
 
         case TYPEDO:
         {