Compile of gnupg-2.2.27 fails on t-keydb.c

[Frank]

Greetings,

I am trying to compile gnupg-2.2.27 and it fails with "syntax error"  
on g10/t-keydb.c.
I was yet unable to gather more informations, what is going wrong.
No line, statement or anything else is given.
   Architecture ppc64
   OS AIX 7.2
   Compiler xlc
Any help is greatly appreciated.

Kind regards
Frank