Mixing uniform and ParameterBlock on Metal returns invalid values

[tdavidovicNV]

I've retested this PR shader-slang/slangpy#283 and while the Vulkan issue (#7431) has been resolved, the test completely fails for Metal, reading back 0.

All other backends pass and so does the existing version of the test on main that is using only uniform, so I assume there is an issue with the Metal codegen as well. This is blocking merging of that PR.

[jkwak-work]

Setting priority as P2 as discussed on Slack with @tdavidovicNV .