commit 5297cd9f821a7a65428f147095934b9a2db4eede
author Daniel Kiss <daniel.kiss@arm.com> Wed Sep 16 23:03:19 2020 +0200
committer Copybara-Service <copybara-worker@google.com> Thu Oct 29 18:05:50 2020 -0700
tree 9d9f6ee91431a1d1b649e70ddd055aa9cf0efcd9
parent db3e650b88c76cc25cfc1a23c075bb1276e744ab

[libunwind] Support for leaf function unwinding.

Unwinding leaf function is useful in cases when the backtrace finds a
leaf function for example when it caused a signal.
This patch also add the support for the DW_CFA_undefined because it marks
the end of the frames.

Ryan Prichard provided code for the tests.

Reviewed By: #libunwind, mstorsjo

Differential Revision: https://reviews.llvm.org/D83573

Reland with limit the test to the x86_64-linux target.

GitOrigin-RevId: 22b615a96593f13109a27cabfd1764ec4f558c7a