sanitizer libraries that already work on FreeBSD:
* asan: Address Sanitizer
* ubsan: Undefined Behavior Sanitizer
* profile: Profile Guided Optimization support
Please note that these libraries are *experimental* at this stage, so
the main Makefile is not yet connected to the build.
Since I didn't want to needlessly edit BSD.usr.dist, you will also have
to create the install directory /usr/lib/clang/3.5.0/lib/freebsd
manually for now.
