[openal] Further consideration of C++

[Daniel Gibson]

Sorry, forgot that I also wanted to address this:

> The libstdc++ mismatch issue can be fixed by OpenAL Soft static-linking 
> it. The system's libopenal won't rely on libstdc++*.so since it'll all 
> be baked into the lib, as if it had coded those things itself in C.

Apparently that doesn't really solve the problem: 
https://bugzilla.redhat.com/show_bug.cgi?id=1417663
Looks like the symbols from a dynamically linked libstdc++ can still 
clash with a statically linked libstdc++ from the system lib..