Roll buildtools/third_party/libunwind/trunk/ 42aa6de55..7ff728a97 (3 commits)

https://chromium.googlesource.com/external/github.com/llvm/llvm-project/libunwind.git/+log/42aa6de5544e..7ff728a9779c

Created with:
  roll-dep buildtools/third_party/libunwind/trunk

Change-Id: If8a643abf0901631ba7727e02d7316e6410ebec5
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/98713
Auto-Submit: K. Moon <kmoon@chromium.org>
Reviewed-by: Nigi <nigi@chromium.org>
Commit-Queue: Nigi <nigi@chromium.org>
Commit-Queue: K. Moon <kmoon@chromium.org>
diff --git a/DEPS b/DEPS
index 68ee1bb..f6b958a 100644
--- a/DEPS
+++ b/DEPS
@@ -110,7 +110,7 @@
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling libunwind
   # and whatever else without interference from each other.
-  'libunwind_revision': '42aa6de5544ec1ccc27da640a044bd3f474ee75a',
+  'libunwind_revision': '7ff728a9779cdc8e0639c032dc45cc20f7b4af21',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling lss
   # and whatever else without interference from each other.