[ASan] Report illegal instruction exceptions in ASan

[ASan] Report illegal instruction exceptions in ASan

Summary:
Respect the handle_sigill common flag and handle_segv flags while we're
at it.

We still handle signals/exceptions differently on Unix and Windows. The
installation process is tricky on Windows, and difficult to push down
into sanitizer_common without concerning it with the different
static/dynamic CRT models on Windows.

Reviewers: kcc, etienneb

Subscribers: llvm-commits, kubabrecka

Differential Revision: https://reviews.llvm.org/D23098

llvm-svn: 277621