spirv: Implement the new ray-tracing storage classes

The SPV_KHR_ray_tracing extension adds 6 new storage classes which is a
bit on the ridiculous side.  In order to avoid adding that many variable
modes to NIR, we make a few simplifying assumptions:

 1. CallableData and RayPayload data actually lives on the stack
    somewhere, presumably in the caller's stack.  We assume that these
    are no different from global variables and use nir_var_shader_temp
    for them.  We still need a separate storage class for the incoming
    variants but only so we can figure out which one the incoming one
    is and lower it to something useful.

 2. There's no difference between incoming CallableData and RayPaolad
    data.  We can use a single storage class for both.

 3. ShaderRecordBuffer data is just a global memory access.  This lets
    us avoid NIR variables entirely and just fetch the pointer via the
    shader_record_ptr system value and it's accessed using a 64-bit
    global memory pointer.

Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6479>

src/compiler/nir/nir_intrinsics.py

@@ -675,6 +675,7 @@ system_value("ray_hit_kind", 1)
 system_value("ray_flags", 1)
 system_value("ray_geometry_index", 1)
 system_value("ray_instance_custom_index", 1)
+system_value("shader_record_ptr", 1, bit_sizes=[64])
 
 # Driver-specific viewport scale/offset parameters.
 #