compile error on HP-UX

Now that HP-UX is back on-line and smoking, we get to pick up the pieces

[2023-02-23 18:54:37+0100] echo @`sh  cflags "optimize='+O2 +Onolimit'" opmini.o`  -DPERL_IS_MINIPERL -DPERL_EXTERNAL_GLOB opmini.c
[2023-02-23 18:54:37+0100] @ccache cc -c -DPERL_CORE -Ae -Wp,-H150000 +Z -z -D_HPUX_SOURCE -Wl,+vnocompatwarnings +DD64 -I/pro/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 +O2 +Onolimit -DPERL_IS_MINIPERL -DPERL_EXTERNAL_GLOB opmini.c
[2023-02-23 18:54:37+0100] "utf8.h", line 109: error #2066: enumeration value is out of "int" range
[2023-02-23 18:54:37+0100]       UTF8NESS_UNKNOWN = (STRLEN) -1,   
[2023-02-23 18:54:37+0100]                          ^

So, (this) HP C-ANSI-C doesn't like the enum to be negative

I think it was added in this commit:

--8<---
Author: Karl Williamson <khw@cpan.org>  2023-01-13 19:17:09
Committer: Karl Williamson <khw@cpan.org>  2023-02-06 18:30:45
Parent: 1f9e96df91d6d0c39aa5ef6636179ebd9e87dc5a (snprintf)
Child:  f14e996faadf17787d10f23d830a5d450a0bbe0b (perl.h: Make sure PERL_IMPLICIT_CONTEXT doesn't come back)
Branch: remotes/origin/smoke-me/khw-env
Follows: v5.37.8
Precedes: 

    locale.c: Remove use of nl_langinfo_l()
    
    I was wrong that it was feasible to determine at Configure time if this
    was a thread safe implementation or not.  What could be determined was
    if it was obviously not thread-safe.  lThe major advantage of using
    this, is hence not valid, so remove the code that handled it specially.
    
    perl.h comments are updated
-->8---

-- 
H.Merijn Brand  https://tux.nl   Perl Monger   http://amsterdam.pm.org/
using perl5.00307 .. 5.37        porting perl5 on HP-UX, AIX, and Linux
https://tux.nl/email.html http://qa.perl.org https://www.test-smoke.org
                           

• compile error on HP-UX by H.Merijn Brand