grep: avoid code duplication with -iF

This follows up on the -iF performance improvement (Bug#23752).
* NEWS: Simplify description of -iF improvement.
* src/dfa.c: Do not include wctype.h.
(lonesome_lower, case_folded_counterparts): Move to localeinfo.c.
(CASE_FOLDED_BUFSIZE): Move to localeinfo.h.
* src/grep.c: Do not include wctype.h.
(lonesome_lower): Remove.
(fgrep_icase_available): Use case_folded_counterparts instead.
Do not call it for the same character twice.
Return false on wcrtomb failures (which should never happen).
(fgrep_to_grep_pattern, main): Simplify.  Let fgrep_to_grep’s
caller fiddle with the global variables.
* src/localeinfo.c: Include <wctype.h>
(lonesome_lower, case_folded_counterparts):
Move here from src/dfa.c.  Return int, not unsigned int.
Verify that CASE_FOLDED_BUFSIZE is big enough.
* src/localeinfo.h (CASE_FOLDED_BUFSIZE): Now 32, so that
we don’t expose lonesome_lower’s size.
* src/searchutils.c (kwsinit): Return new kwset instead of
storing it via a pointer.  All callers changed.  Simplify a bit.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/kwsearch.c b/src/kwsearch.c
index 7fe08aa4..29d140cd 100644
--- a/src/kwsearch.c
+++ b/src/kwsearch.c
@@ -38,7 +38,7 @@ Fcompile (char const *pattern, size_t size)
 {
   size_t total = size;
 
-  kwsinit (&kwset, true);
+  kwset = kwsinit (true);
 
   char const *p = pattern;
   do