This is what I have installed:
What version of linux-headers do you have installed? I believe this is complaining about a missing /usr/include/linux/compiler.h, but I don't have that file either.
root@smoker / # equery list linux-headers
[ Searching for package 'linux-headers' in all categories among: ]
* installed packages
[I--] [ ~] sys-kernel/linux-headers-2.6.19 (0)
root@smoker / #
-- www.myspace.com/dalek1967