Pixel shader 1.x constants must be between -1 and 1, or they will be clamped,
even constants defined in the shader.
Also mark 1.x-specific features if any.
When the client acquires the Vulkan queue it has to ensure that
it is not submitting work before other work it depends on already
submitted through the Direct3D 12 API but currently in the internal
vkd3d queue. Currently we suggest to enqueue signalling a fence and
than wait for it before acquiring the Vulkan queue, which is
correct but excessive: it will wait not just for the work currently
in the queue to be submitted, but for it to be executed too,
introducing useless dependencies.
By adding a way to enqueue signalling a fence on the CPU side we
allow the client to wait for the currently outstanding work to
be submitted to Vulkan, but nothing more.
Commit 1ed8d907b3 inadvertently dropped
emitting the tessellator domain for domain shaders. Although Vulkan
environments allow us to write the tessellator domain from the hull
shader, the domain shader, or both, that's not generally true for OpenGL
environments.
