fmgr changes not yet ported to AIX

Just wanted to give a short message, that current snapshot does not
compile on AIX due to the fmgr changes.
I have some patches that unfortunately affect other ports but not a complete
fix.
Why are the pg_dlopen ... declared extern in include/utils/dynamic_loader.h
?

aside: Why is sys/fcntl.h included in c.h and not in config.h ?
AIX has fcntl.h, but that seems not to be compatible with dlfcn.h.
It does not seem to be missing if commented out.

Andreas

PS: Am I the only looser who now looking at the new fmgr interface has his
doubts
about the changes ?

What exactly does it gain except masking badly written code
(casts to wrong datatype like ints to longs) that goof the optimizers and
64bit ports
and solving the null value problem ?

My ideas would be:
- multi row returns
- multi column returns (not opaque)
- portability to other implementations
(Informix is similar to our old fmgr interface,
Oracle's interface I think is not open to the public)

It would e.g. have been possible to add the NULL indicator array as last
argument
to the existing scheme. Informix reserves one value of each pass by value
datatype
to represent NULLs which imho is a bad idea (e.g. INT_MIN for int's).