[PATCH] Enable running Ubsan tests on FreeBSD

[Ed Maste]

================
Comment at: test/ubsan/lit.common.cfg:50
@@ -49,3 +49,3 @@
 # UndefinedBehaviorSanitizer tests are currently supported on
-# Linux and Darwin only.
-if config.host_os not in ['Linux', 'Darwin']:
+# Linux, Darwin and FreeBSD only.
+if config.host_os not in ['Linux', 'Darwin', 'FreeBSD']:
----------------
This comment is identical to the test that immediately follows so seems redundant.

Perhaps:
```
# Check that the host supports UndefinedBehaviorSanitizer
if config.host_os not in ...
```

http://reviews.llvm.org/D6089