[patch][plugins] Provide unique names to all compiler passes

[Joern Rennecke]

Quoting Richard Guenther <richard.guenther@gmail.com>:

> On Fri, Nov 6, 2009 at 3:10 PM, Joern Rennecke <amylaar@spamcop.net> wrote:
>> Quoting Richard Guenther <richard.guenther@gmail.com>:
>>>
>>> Ok.  The patch is ok after waiting another 24h to let others
>>> the time to comment.
>>
>> The one with STX or with '@' ?
>
> I personally prefer '@' here.

It just occurred to me that we could use a space.  That character
must not be part of an option name and therefore is taboo for
the dump options, and even if we could make it part of a dump
file name it would be a rather odd thing to do; on the other hand,
it will look fine both in the source code and when printing out
the name for debug purposes.
Also, it gives us good portability across character sets.