[PATCH] [Msan] Fix some interceptors to pass initialization on FreeBSD

[Viktor Kutuzov]

> In fact, I've seen getenv() on linux not working properly during MSan initialization, because it happens in .preinit_array and environ is simply not set at this point.
> Just FYI. If msan_init somehow caused getenv() call, it might be getting unexpected results.

Just checked it and it looks getenv() is fully workable at the moment of its first call. Thanks.

http://reviews.llvm.org/D6417