Enable LLVM's built-in stack trace code. This intercepts the OS's crash signals and prints which component of LLVM you were in at the time if the crash.
Install a fatal error handler. By default, if LLVM detects a fatal error, it will call exit(1). This may not be appropriate in many contexts. For example, doing exit(1) will bypass many crash reporting/tracing system tools. This function allows you to install a callback that will be invoked prior to the call to exit(1).
Reset the fatal error handler. This resets LLVM's fatal error handling behavior to the default.