Removing -frename-registers from -O3

[Geoff Keating]

Bernd Schmidt <bernds@redhat.com> writes:

> how do you feel about this patch?  IMO -frename-registers is too harmful
> to debugging to include it by default on any target (except ia64 for
> which it's uncommonly useful).

If we do this, can we have an -O4 which means 'best possible
optimisation even if that breaks source code debugging'?  That could
also add -fomit-frame-pointer.

-- 
- Geoffrey Keating <geoffk@geoffk.org>