Pulling in libwayland causes undefined symbols in applications that are
linked against vulkan alone. Ideally, we would like to dlopen a platform
support library or something like that. For now, this works and should get
crucible running again.
We do this for two reasons: First, because it allows us to simplify WSI and
compiling in/out support for a particular platform is as simple as calling
or not calling the platform-specific init function. Second, the
implementation gives us a place for a given chunk of the WSI to stash
stuff in the instance.
Unfortunately, this is a very large commit and removes the old LunarG WSI
extension. This is because there are a couple of entrypoints that have the
same name between the two extensions so implementing them both is
impractiacl.
Support is still incomplete, but this is enough to get vkcube up and going
again.
Jason Ekstrand