Bisecting 3 year old kernels?

[Bruno Wolff III]

I have a couple of old bugs that still affect me and want to see if I can 
do a bisect on a rawhide machine of the older kernels (e.g. 2.6.37, 2.6.35). 
So far I have been hitting a problem with a gcc error mentioning 
conflicting types in a case where asmregparm is used in one place and not 
another.

Am I going to need to use something like mock to do these builds?

Is there any hope that I can run the resulting kernel on rawhide? (I need 
to test that X works in one case and motherboard sound combined with 
high network traffic works in the other.)

Even if I need to test the kernels on an older Fedora, it would be nice to 
do the builds on a rawhide machine so that I can use the rawhide machine 
while the builds are being done and only do the tests on an older Fedora.