OpCopyObject lets you sidestep OpSampledImage validation

There is a `spirv-val` error

> All OpSampledImage instructions must be in the same block in which their Result are consumed

but now learning from @alan-baker in https://github.com/KhronosGroup/SPIRV-Guide/issues/27 we should not be able to side-step with `OpCopyObject`

For GPU-AV in the Vulkan Validation Layers, I have times I need to go

```swift
%result = OpLoad %1 %2

// <----- Inject an if check to make sure this access to something unrelated doesn't blow up when executed
%bad_accsss = OpAccessChain
%bad_load = OpLoad %bad_accsss

%5 = OpSampledImage %3 %4 %result
```

and my "fix" was using `OpCopyObject` to pass `%result` so that `spirv-val` didn't complain :shrug:

1. I got from @dneto0 at the F2F this was not intended
2. While here, any suggestions how something like GPU-AV should work around this case?