In order to use the Vulkan 1.2 core viewport and layer shader outputs,
we need to use SPIR-V 1.5. But we've recently added some preliminary
support to compute the SPIR-V version we're using, with the intention of
adding a SPIR-V version override to work around bugs in tools like
RenderDoc. We haven't implemented the latter yet.
But just to be safe, let's limit this to SPIR-V 1.5. This isn't going to
matter right now, but it might avoid a problem if we decide to finish up
the SPIR-V version overriding.
Reviewed-by: Hoe Hao Cheng <haochengho12907@gmail.com>
Reviewed-By: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11259>
6e2d8ab808