r189218 - Simplify now that -O4 just maps to -O3 and -O is an alias of -O2.

[Rafael Espíndola]

> Ok, makes sense.  Those uses can use an explicit -O1 though :-)

Sure.

>> I haven't seen -O being used in wild, so I OK with keeping it mapping to -O2.
>
> I'd be curious to know how many files in a linux distro are built with -O.  I wouldn't be surprised if it is  5-10%.

Sylvestre might know how to answer that :-)

Cheers,
Rafael