Add sources.py `prune` subcommand to prune unrequired sources

This command should make it easier to prune unrequired sources after
copying a new version of libunwindstack and required subfolders into the
src/ directory.

After writing this command, I then ran it, which removed parseint.h.
This file was required by logging.cpp, which was in my original local
compiling version of libunwindstack but was later removed from the
library via a patch.

Bug: 991960
Change-Id: I422caf2c386aadbd046caced3d1dfef6a389e74d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/third_party/libunwindstack/+/1900012
Reviewed-by: Mike Wittman <wittman@chromium.org>
3 files changed
tree: e2844c91598b54c49551afb177b95572cdf8ed38
  1. .clang-format
  2. BUILD.gn
  3. LICENSE
  4. OWNERS
  5. README.chromium
  6. patches/
  7. src/
  8. tools/