Dynamic linkers use `struct r_debug` and `struct link_map` (defined in
`<link.h>`) to communicate lists of loaded modules to debuggers.
Bug: crashpad:30
Change-Id: Id903a1c199288dd85c34e38710cdb4c6b5fedb5b
Reviewed-on: https://chromium-review.googlesource.com/534853
Reviewed-by: Mark Mentovai <mark@chromium.org>
