#153975 added a new test,
`test/CodeGen/AMDGPU/disable-preload-kernargs.ll`, that triggers an
assertion under `LLVM_ENABLE_EXPENSIVE_CHECKS` complaining about not
invalidating analyses even when the Pass made changes. It was caused by
the fact that the Pass only invalidates the analyses when number of
explicit arguments is greater than zero, while it is possible that some
functions will be removed even when there isn't any explicit argument,
hence the missed invalidation.
The existing `amdgpu-kernarg-preload-count` can't be used as a switch to
turn it off if it is set to 0. This PR adds an extra option to turn it
off.
Fixes SWDEV-550147.
This flag was used to let us incrementally introduce debug records
into LLVM, however everything is now using records. It serves no
purpose now, so delete it.
Moves kernarg preload logic to its own module pass. Cloned function
declarations are removed when preloading hidden arguments. The inreg
attribute is now added in this pass instead of AMDGPUAttributor. The
rest of the logic is copied from AMDGPULowerKernelArguments which now
only check whether an arguments is marked inreg to avoid replacing
direct uses of preloaded arguments. This change requires test updates to
remove inreg from lit tests with kernels that don't actually want
preloading.
