Since commit 35d2f1e87 the MHR demo crashes on launch, presumably because of invalid spirv:

#0  0x00007ffbed87a9bf in radv_shader_compile_to_nir ()
#1  0x00007ffbed85925b in radv_create_shaders ()
#2  0x00007ffbed8640b4 in radv_compute_pipeline_create ()
#3  0x00007ffbed8644cb in radv_CreateComputePipelines ()
#4  0x00007ffbee127608 in  ()
#5  0x00007ffbf24a9204 in wine_vkCreateComputePipelines ()
#6  0x000000035e500ed6 in d3d12!D3D12CreateDevice ()
#7  0x0000000000000db0 in  ()
#8  0x0000000000000000 in  ()

spirv-val:

error: line 4861: A block must end with a branch instruction.
  %4371 = OpLabel

2adfe544a7f1e163.spv
error: line 907: A block must end with a branch instruction.
  %1053 = OpLabel

5abe9cfdf4b1f914.spv
error: line 4868: A block must end with a branch instruction.
  %4541 = OpLabel

042b5c2fc76a9f1a.spv
error: line 898: A block must end with a branch instruction.
  %881 = OpLabel

c51700579196abef.spv

Seems to only happen on drivers where SM6.6 gets exposed according to the vkd3d-proton log, i.e. RADV/LLVM and AMDVLK don't crash.
The dumped shaders
MHR-shaders.zip
: