gawk: update to version 5.2.1

gawk: update to version 5.2.1

Changes from 5.2.0 to 5.2.1
---------------------------

1. Infrastructure upgrades: PMA version Avon 8.

2. Issues related to the sign of NaN and Inf values on RiscV have
   been fixed; gawk now gives identical results on that platform as
   it does on others.

3. A few issues with the debugger have been fixed.

4. More subtle issues with untyped array elements being passed to
   functions have been fixed.

5. The rwarray extension's readall() function has had some bugs fixed.

6. The PMA allocator is now supported on FreeBSD, OpenBSD and Linux on S/390x.
   Is is now supported also on both Intel and M1 macOS systems.

7. There have been several minor code cleanups and bug fixes. See the
   ChangeLog for details.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>