[oe] [rfc] change default for BUILD_OPTIMIZATION, remove spurious assignments

[Phil Blundell]

On Tue, 2009-06-23 at 10:30 -0700, Khem Raj wrote:
>  -frename-registers was a workaround to get past a ARM GCC ICE in 4.2 IIRC
> we should get rid of it.

No, -frename-registers is an optimisation in its own right.  I think we
probably want to keep that.  You might be thinking of the
-fno-rename-registers that we do use for some packages to avoid an ice
on arm with gcc 3.4.

> -fexpensive-optimizations and -fomit-frame-pointer are passed by
> default at O2 so we should get rid of them too.

Is that true on all targets?  I didn't think that -O2 implied
-fomit-frame-pointer on arm.

p.