__property keyword support in GCC

[Joe Buck]

> 	I'm personally a big fan of Borland's compilers. However, its always
> been a policy to refrain from using vendor extensions or even their
> implementations of standard libraries. This policy has served me very
> well and, while YMMV, I expect you'd see similar results. Pretty much
> the main odd extensions that remain are ones that Linux kernel source
> (and possibly GNU c-lib?) have been dependent upon for some time. I'd
> personally like to see these go away but there are many not-so-good
> and a few really-good reasons why this won't happen any time soon.

I'd put those extensions into three categories:

1) Inline assembly support;
2) Attributes that give the compiler more information, to permit better
   optimization;
3) Well-designed extensions we're likely to see added to things like C9X;
4) Other stuff.

IMHO I'd only want things in category 4 to go away, though the line
between #3 and #4 is sometimes fuzzy.  We've paid a price in the past
because some of these extensions were not rigorously documented.