Add a check for strtoll for libevent.

Not having this check was causing distcheck errors on the OMPI
tarball-build machine because it's still a 32-bit-default machine, so
the evutil.c code was failing some #if conditionals (since it didn't
think it had strtoll available).

This commit was SVN r22577.

opal/config/opal_setup_libevent.m4

@@ -68,7 +68,7 @@ dnl Checks for typedefs, structures, and compiler characteristics.
 AC_HEADER_TIME
 
 dnl Checks for library functions.
-AC_CHECK_FUNCS(gettimeofday vasprintf fcntl)
+AC_CHECK_FUNCS(gettimeofday vasprintf fcntl strtoll)
 
 AC_MSG_CHECKING(for F_SETFD in fcntl.h)
 AC_EGREP_CPP(yes,