Porting to Concurrent PowerMAX OS

[Bates, Rod]

I am trying to port to Concurrent PowerMAX OS. 
config.guess doesn't recognize it.  The closest thing in config.guess
is powerpc-harris-powerunix.  This company used to be Harris,
and their os used to be called PowerUnix.  

But configure won't recognize powerpc-harris-powerunix :-( .
I have tried powerpc-harris-sysv, as my best guess.  
This dies because of a header file inconsistency in
declaring alloca.  This problem looks like it would go away if 
_AIX were defined, which I presume would happen if I
specified some flavor of AIX, but this doesn't seem
very likely to me to be right.  

Furthermore, attempting to build Gnu Make, which intends
to do all configuration automatically, fails with the same
conflict (in different source files).  Configure in make does
not set the _AIX macro.  

I would appreciate any info on the geneology of this OS.  
Header files contain "Unix Systems Labs" in comments.  

The specific conflict is this:  /usr/include/stdlib.h contains
extern void *alloca(size_t); 
Gnu source files, with the macros as set by configure, contain
extern char *alloca(); 

Rodney Bates