[openal] Distro build changes

[Chris Robinson]

Hey folks.

I have a question for people that are handling OpenAL Soft's distro 
packages. I'm looking at a pull request that changes the build variables 
it's been using, LIB_SUFFIX and SHARE_INSTALL_DIR, to use the 
standard(?) GNUInstallDirs module, which provides CMAKE_INSTALL_LIBDIR, 
CMAKE_INSTALL_DATADIR, etc:

https://github.com/kcat/openal-soft/pull/63

I think it would be a good move to use these, but I want to make sure 
it's not going to cause a problem, and to make sure you're aware of the 
change.


Secondly, it seems some systems require the use of libatomic to use 
certain C11 atomic functions. Checking for and linking with this lib 
when it's available isn't a problem, however I've noticed that when I 
link to it, it becomes a run-time dependency even if it wasn't actually 
required. Checking if it's required isn't so straight forward since 
different CPU targets may need it for different reasons (e.g. SPARC 
requires libatomic for atomic_fetch_add, while another CPU may instead 
need it for 64-bit types).

So I'd like to make sure that linking libatomic when it's available, 
even if it's not used for a given target, would be alright. Or if 
there's another suggestion to only linking it on targets that really 
need it.