Fixing valid options for std.getopt

[Jonathan M Davis]

> On 10.08.2011 2:35, Bernard Helyer wrote:
> > On Tue, 09 Aug 2011 22:34:29 +0000, Bernard Helyer wrote:
> >> For SDC I've had to resort to filtering through args before getopt and
> >> replacing -m32 with --m32. The output flag needs to have that treatment
> >> too (seriously, `sdc -o=foo.bin foo.d` is just weird). I lurve these
> >> changes and give them two thumbs up.
> >> 
> >> d-n_n-b
> > 
> > That said, I would like -ofoo.bin to work as well. Perhaps a flag to
> > allow it?
> 
> Same here, though not a big deal.
> Taking Jonathan's comment into account, how about allowing it when
> bundling of arguments is disabled?

I'm not sure that it's a bad idea to give some options on how getopt works 
(e.g. a way to disallow the bundling of arguments), but in general it should 
probably work like the C getopt as far as what it accepts goes, and I believe 
that these changes bring it more in line with the C getopt.

Typically, the only way to use multi-character flags is --, and when you use 
-, every all of the characters immediately following it are individual flags. 
It's _very_ odd for dmd to have flags which are multi-character but only take 
a single -, and I'd argue that that's not behavior which should be emulated.

So, in general, I think that these changes are very much the right approach. 
However, it may be reasonable to have a way to alter some of getopt's behavior 
for those who want it.

- Jonathan M Davis