yy_fatal_error calls exit(), so it should be declared

noreturn (improves optimisation of things that call it

and makes -Wmissing-noreturn happy).

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=189784

--- flex/flex.skl

+++ flex/flex.skl

@@ -734,7 +734,11 @@ m4_ifdef( [[M4_YY_NOT_IN_HEADER]],

 static yy_state_type yy_get_previous_state M4_YY_PARAMS( M4_YY_PROTO_ONLY_ARG );

 static yy_state_type yy_try_NUL_trans M4_YY_PARAMS( yy_state_type current_state  M4_YY_PROTO_LAST_ARG);

 static int yy_get_next_buffer M4_YY_PARAMS( M4_YY_PROTO_ONLY_ARG );

+#ifdef __GNUC__

+static void yy_fatal_error M4_YY_PARAMS( yyconst char msg[] M4_YY_PROTO_LAST_ARG ) __attribute__((noreturn));

+#else

 static void yy_fatal_error M4_YY_PARAMS( yyconst char msg[] M4_YY_PROTO_LAST_ARG );

+#endif

 ]])

 %endif