This has been tested on the following platforms against the git/master 
(and 5.5.1)

Solaris 11.4 (x86) Developer Studio

FreeBSD 13.1 clang

Centos 7 gcc

Rocky 8 gcc

Rocky 9 gcc

HP-UX 11.31 HP ANSI C compiler


I'd appreciate if someone would test it on a few other platforms and try 
to break it.  I tried everything I could think of, but...