[clang] [clang-tools-extra] [llvm] [LLVM][CLANG] Update signal-handling behavior to comply with POSIX (PR #169340)

[Xing Xue via cfe-commits]

xingxue-ibm wrote:

> LLVM Buildbot has detected a new failure on builder `sanitizer-x86_64-linux-android` running on `sanitizer-buildbot-android` while building `clang,llvm` at step 2 "annotate".
> 
> Full details are available at: https://lab.llvm.org/buildbot/#/builders/186/builds/16383
> Here is the relevant piece of the build log for the reference

After the failing build 16383, build 16385 was successful at: https://lab.llvm.org/buildbot/#/builders/186/builds/16385

https://github.com/llvm/llvm-project/pull/169340