Use strchr, strrchr instead of index, rindex

Use strchr, strrchr instead of index, rindex

* callint.c (Fcall_interactively): Use strchr, strrchr instead of
index, rindex.
* doc.c (get_doc_string, Fsnarf_documentation): Likewise.
* editfns.c (Fuser_full_name, Fformat): Likewise.
* emacs.c (argmatch, sort_args, decode_env_path): Likewise.
* fileio.c (Ffile_symlink_p): Likewise.
* filelock.c (current_lock_owner): Likewise.
* font.c (font_parse_name, font_parse_family_registry): Likewise.
* fontset.c (fontset_pattern_regexp): Likewise.
* lread.c (read1): Likewise.
* sysdep.c (init_system_name): Likewise.
* xfns.c (select_visual): Likewise.
* s/hpux10-20.h (index, rindex): Don't define.
* s/ms-w32.h (index): Likewise.
* s/usg5-4.h: Likewise.

* sed2v2.inp (HAVE_INDEX, HAVE_RINDEX): Don't edit.
(HAVE_STRCHR, HAVE_STRRCHR): Edit to 1.

* emacsclient.c (set_local_socket): Use strchr, strrchr instead of
index, rindex.
* movemail.c (mail_spool_name, popmail): Likewise.
* pop.c (pop_list): Likewise.

* CPP-DEFINES (HAVE_INDEX, HAVE_RINDEX): Remove.

* configure.in: Don't check for index and rindex, check for strchr
and strrchr.  Define strchr and strrchr as index and rindex,
resp., in src/config.h if not available.