Package: grep

When don't pass backref parameter to dfaexec(), a DFA state which is built
previously may be re-built.

In non-UTF8 locales, when reach a state which mbps aren't empty, exit
main loop and call build_state() in dfa.c, even if the state has been
already built.

That will cause increase of processing time, and waste of a lot of
memories.

Fortunately, grep program doesn't pass the code in dfa.c unless
mblen_buf overflows, since backref parameter is specified when dfaexec()
is called with large buffer.

Norihiro