[PATCH] Add FreeBSD 9 support to libcxxabi testing framework

[Eric Fiselier]

What was this patch generated against? It seems to be against a old and very customized version of lit.cfg. 
Please generate the diff against the master. I'm very interested in seeing this patch in master ASAP. However the patch you submitted will not work unless you submit the rest of your changes as well.

Some points:
- We still need to handle the cxxrt ABI.
- llvm_unwinder is not set anywhere (in master) but I'm very interested to see it supported.
- Please add freebsd to the locales table (in master). Here is the change I made to get it working:
```
'FreeBSD' : {
        'en_US.UTF-8': 'en_US.UTF-8',
        'cs_CZ.ISO8859-2': 'cs_CZ.ISO8859-2',
        'fr_FR.UTF-8': 'fr_FR.UTF-8',
        'fr_CA.ISO8859-1': 'fr_CA.ISO8859-1',
        'ru_RU.UTF-8': 'ru_RU.UTF-8',
        'zh_CN.UTF-8': 'zh_CN.UTF-8',
    },
```

Thanks for working on this.

http://reviews.llvm.org/D4925