Summary:
Part of https://github.com/google/sanitizers/issues/637
Standalone ubsan needs signal and sigaction handlers and interceptors.
Plugin mode should rely on parent tool.
Reviewers: eugenis, alekseyshl
Subscribers: kubamracek, llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D37895
llvm-svn: 314052
Vitaly Buka