DynamicLoader doesn't look for loader in /usr/local/lib on macOS

[ivirtex]

Vulkan SDK loader is usually installed in /usr/local/lib on macOS.
DynamicLoader should look into this path as a potential place to find the loader, since new macOS versions don't look there by default.

[tomadamatkinson]

I can confirm that i get this issue on MacOS after updating to the latest OS

[asuessenbach]

@tomadamatkinson and @ivirtex Would you please verify, if this #1991 actually resolved this issue?

[ivirtex]

Will this change be reflected in Vulkan-Headers repo?

[asuessenbach]

@ivirtex Sure, some time after this change gets merged (that is, after you and/or @tomadamatkinson verified that it resolves this issue) it will be part of the Vulkan-Headers repo.

[squidbus]

Could this be adjusted to prefer /usr/local/lib/libvulkan.dylib over libMoltenVK.dylib? libvulkan is needed to use layers, but currently if the app bundles in a libMoltenVK.dylib and the user has the SDK installed using /usr/local/lib, libMoltenVK is always loaded directly instead and layers aren't supported.

The app bundles in libMoltenVK.dylib so that users don't need to install a separate Vulkan SDK to use the app, but my intent is that if the user has the SDK installed it will use libvulkan and allow enabling the validation layer.