System.map instead of vmlinux

[Brian E. <eat...@gm...>]

Attached is a slightly more polished version of the System.map patch.
Mostly I've made the parsing of the System.map file more robust.

Known problems:
- this is closer to working on 64-bit machines, but probably still won't work.
- still no mechanism to verify that the System.map file matches the
running kernel.  There appears to be a similar problem for vmlinux
files.  I'm open to suggestions on how to fix this.  Maybe
/proc/ksyms?

There is also an open question as to whether this patch is worth
doing.  After all, how hard is it to get a vmlinux file?  The patch
may be useful for a few reasons:

- some major linux distributions don't ship vmlinux files.  RedHat and
Fedora make them available, but it takes some time to pull them down.
Ubuntu and Debian don't seem to make them available at all.  I work
mostly on RedHat and Ubuntu, so for me this patch is a time-saver.

- disk space limitations.  For example:
http://marc.theaimsgroup.com/?l=oprofile-list&m=115124224324015&w=2

- this patch might morph into a useful intermediate file format for
dynamically generated symbols:
http://marc.theaimsgroup.com/?l=oprofile-list&m=115619608118310&w=2

Regards,
Brian