[PATCH] unwinder: fully support linker generated .eh_frame_hdr section

Now that binutils' ld is able to properly populate .eh_frame_hdr in the
Linux kernel case, here's a patch to add some functionality to the Dwarf2
unwinder to actually be able to make use of this (applies on firstfloor
tree with the previously sent patch to add debug output, but not on plain
2.6.19).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>