Revert "Attempt to remove deprecated sv_locking/unlocking"

[khwilliamson]

This reverts commit 3afafdb.

It turns out that Perl_sv_nounlocking() is the mechanism that is used to make sure mathoms.c gets loaded, as the comments in the reverted commit say, but which I had not noticed.

Without this function being in mathoms.c, some build configurations will not load mathoms, leaving other functions in mathoms.c undefined, as happened with the two issues this fixes.

This commit could be reinstated if another method is created to force mathoms to be loaded;

This fixes #23473
This fixes #23474

• This set of changes requires a perldelta entry, and it is included.

[jkeenan]

Once this p.r. is applied, the deprecations are clearly indicated in the respective modules' build-time warnings.

Unicode::UTF8

In file included from UTF8.xs:6:
ppport.h:4594: warning: "WIDEST_UTYPE" redefined
 4594 | #  define WIDEST_UTYPE U64TYPE
      | 
In file included from /home/jkeenan/testing/gh-23475-khwilliamson-revert_unlocking-20250725/lib/perl5/5.43.2/x86_64-linux/CORE/perl.h:3297,
                 from UTF8.xs:3:
/home/jkeenan/testing/gh-23475-khwilliamson-revert_unlocking-20250725/lib/perl5/5.43.2/x86_64-linux/CORE/handy.h:1417: note: this is the location of the previous definition
 1417 | #define WIDEST_UTYPE PERL_UINTMAX_T
      | 
UTF8.xs: In function ‘xs_utf8_encode_replace’:
UTF8.xs:329:9: warning: ‘Perl_utf8n_to_uvuni’ is deprecated [-Wdeprecated-declarations]
  329 |         v = utf8n_to_uvuni(src, len, &skip, (UTF8_ALLOW_ANYUV|UTF8_CHECK_ONLY) & ~UTF8_ALLOW_LONG);
      |         ^
In file included from /home/jkeenan/testing/gh-23475-khwilliamson-revert_unlocking-20250725/lib/perl5/5.43.2/x86_64-linux/CORE/perl.h:6162:
/home/jkeenan/testing/gh-23475-khwilliamson-revert_unlocking-20250725/lib/perl5/5.43.2/x86_64-linux/CORE/proto.h:6136:1: note: declared here
 6136 | Perl_utf8n_to_uvuni(pTHX_ const U8 *s, STRLEN curlen, STRLEN *retlen, U32 flags)
      | ^~~~~~~~~~~~~~~~~~~
rm -f blib/arch/auto/Unicode/UTF8/UTF8.so
cc  -shared -O2 -L/usr/local/lib -fstack-protector-strong  UTF8.o  -o blib/arch/auto/Unicode/UTF8/UTF8.so  \
      \
  
chmod 755 blib/arch/auto/Unicode/UTF8/UTF8.so
  CHANSEN/Unicode-UTF8-0.62.tar.gz
  /usr/bin/make -- OK

JSON::XS

cc -c   -fwrapv -fno-strict-aliasing -pipe -fstack-protector-strong -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -O2   -DVERSION=\"4.03\" -DXS_VERSION=\"4.03\" -fPIC "-I/home/jkeenan/testing/gh-23475-khwilliamson-revert_unlocking-20250725/lib/perl5/5.43.2/x86_64-linux/CORE"   XS.c
XS.xs: In function ‘decode_utf8’:
XS.xs:207:5: warning: ‘Perl_utf8n_to_uvuni’ is deprecated [-Wdeprecated-declarations]
  207 |     return utf8n_to_uvuni (s, len, clen, UTF8_CHECK_ONLY);
      |     ^~~~~~
In file included from /home/jkeenan/testing/gh-23475-khwilliamson-revert_unlocking-20250725/lib/perl5/5.43.2/x86_64-linux/CORE/perl.h:6162,
                 from XS.xs:2:
/home/jkeenan/testing/gh-23475-khwilliamson-revert_unlocking-20250725/lib/perl5/5.43.2/x86_64-linux/CORE/proto.h:6136:1: note: declared here
 6136 | Perl_utf8n_to_uvuni(pTHX_ const U8 *s, STRLEN curlen, STRLEN *retlen, U32 flags)
      | ^~~~~~~~~~~~~~~~~~~
rm -f blib/arch/auto/JSON/XS/XS.so
cc  -shared -O2 -L/usr/local/lib -fstack-protector-strong  XS.o  -o blib/arch/auto/JSON/XS/XS.so  \
      \
  
chmod 755 blib/arch/auto/JSON/XS/XS.so
cp bin/json_xs blib/script/json_xs
"/home/jkeenan/testing/gh-23475-khwilliamson-revert_unlocking-20250725/bin/perl" -MExtUtils::MY -e 'MY->fixin(shift)' -- blib/script/json_xs
  MLEHMANN/JSON-XS-4.03.tar.gz
  /usr/bin/make -- OK