Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r228269,228921:

- libc: Eliminate 13 relative relocations in wctype().
- libc: Eliminate some relative relocations in setlocale().

MFC the xlocale implementation.

Merged revisions: 227487,227753,227807,227818,227999,228002,228875,230156,231673,232498,232601,232620,232626,232926-232927,232929,232931,232935,233173,233600,234573,234578,235239

This currently defines __NO_TLS on ARM (unlike head), because the required
support function has not been MFC'd.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Don't allocate the constant array "props" on the stack in wctype.

PR: 74743
Submitted by: knut st. osmundsen
Approved by: rwatson (mentor)
MFC after: 1 month

Recognize the "rune" character class in wctype().

Change wctype_t to an unsigned type to avoid warnings.

Add ISO C90 Amd. 1 wctype(3) and iswctype(3) functions.