speedup collect2 (by not using it)

[David Edelsohn]

>>>>> Matt Austern writes:

Matt> But in any case, isn't this a bit tangential to the question Mike
Matt> asked?  He asked what happens on systems where USE_COLLECT2
Matt> *isn't* defined, and you're talking about systems where it is (or at 
Matt> least was) defined.

	Mike asked about AIX and systems with ctor requirements like AIX.
Those system define use_collect2=yes.

David