QNX6 port (need some assistance from developers)

Hello list,

I am trying to do QNX6 (aka QNX/Neutrino aka QNX RTP) port. It builds
(7.2b2) and mostly works already, but some regression tests fail.
There's some usual stuff like discrepancies in float formatting and
timezones which I can deal with, but some failures are rather deep.

In particular:

1. some numeric tests fail with:
ERROR: Can not create unique index. Table contains non-unique values.

2. one of the oidjoins tests gives unexpected row(s) (sometimes 1,
sometimes 2), when expected 0.

3. all create view tests fail with:
ERROR: Cannot insert a duplicate key into unique index
pg-rewrite_rulename_index

4. in some of privileges tests select produces 0 rows when it expects 1.

The released 7.1.3 has same problems, plus it exhibits signs of memory
corruptions (at least on QNX6), so 7.2b2 is really much better.

The compiler is GCC 2.95.2, C library is Dinkum (claims to be 100% ANSI
compliant). CPU is Pentium, linker is GNU LD (this is ELF platform) so
shared libs are supported and there are no issues related to that.
There's no modifications in code aside from addition of SYS5 sem/shm
emulation stuff, like for QNX4. Locking code is standard i386 assembly,
I also tried mutex-based locking and it works same way.

I need help from someone to understand reasons for those failures. I'm
pretty knowleageable about the platform.
Attached are results of above mentioned tests.

Thanks,
- Igor