Add a few unwinder tools to debug tools.

These tools are useful for dumping elf information. Also, some of the
scripts in development are being modified to use some of these tools,
specifically, unwind_symbols.

Test: Do a clean userdebug build and verify that the tools are built.
Change-Id: Id26b8d2220dc542e8aa73d4b701916fa3d2ea804
Merged-In: Id26b8d2220dc542e8aa73d4b701916fa3d2ea804
(cherry picked from commit 6605dc01)