RFR: 8240110: Improve NULL

[Thomas Stüfe]

<snip>

And #define'ing NULL as 0 may be actively wrong for the reasons
> discussed in the #ifdef SOLARIS definition in globalDefinitions_gcc.hpp.
> The referenced bug says something like that code was needed for a
> broken standard library on some unknown proprietary OS; it's unclear why
> that code is conditionalized on SOLARIS, since the bug seems to suggest
> that Solaris header actually do the right thing.  Note also that this
> code is deprecated by JEP 362.
>
> It would be interesting to find out if the AIX problem with dirent.h
> unconditionally redefining NULL still exists.
>
>
As of AIX 7.2, it still exists.

Cheers, Thomas