[gentoo-embedded] Auto Repair Cross Includes?

[Ned Ludd]

I've been toying with an idea after seeing a patch which would abort()
when it detected host includes for cross compiles. I did not like the
idea of aborting as it prevented me from building pkgs that had the same
headers in $ROOT as /. I did like the fact there was a little QA I could
slip in there. After thinking about it a while. I said fsck the QA and
just fixed the problem. Here is what I came up with for gcc-4.2.4.. 

While in my testing I'm finding this works beautifully. However I'd like
some input from others on what they think of such an idea. 
Good/Bad/Other?

Basic goal detect ^/usr/include and rewrite it to $ROOT/usr/include if
using a cross compiler and ROOT is set.


-solar