* defs.h (enum openp_flags): New enum.
(OPF_TRY_CWD_FIRST, OPF_SEARCH_IN_PATH, OPF_RETURN_REALPATH):
Move to enum openp_flags.
(openp_flags): New enum flags.
(openp): Change parameter type to openp_flags.
* source.c (openp): Change parameter type to openp_flags.
* cli/cli-cmds.c (find_and_open_script): Use openp_flags.
* dwarf2read.c (try_open_dwop_file): Use openp_flags.