And a few variables around.
There remain cases where the accepted pointer is const, yet the returned
pointer is written to.
Partly addressing (glibc 2.43):
```
* For ISO C23, the functions bsearch, memchr, strchr, strpbrk, strrchr,
strstr, wcschr, wcspbrk, wcsrchr, wcsstr and wmemchr that return
pointers into their input arrays now have definitions as macros that
return a pointer to a const-qualified type when the input argument is
a pointer to a const-qualified type.
```
Ref: https://lists.gnu.org/archive/html/info-gnu/2026-01/msg00005.html
Reported-by: Rudi Heitbaum
Ref: #20420Closes#20421