Check PSyclone checksums

According to comments in the code, the PSyclone step hashes only the metadata of a PSyclone kernel, not the whole file.

That means that if a transformation script uses (module) inlining, and the implementation of a kernel changes, this will get undetected. While the new kernel will be compiled, PSyclone will not run again, and therefore the PSy-layer will keep on using the old implementation.

Start by locating the PSyclone build step and the code comments describing its checksum inputs. Reproduce the module-inlining case and trace when the checksum is compared; the work is done when a changed kernel implementation invalidates the checksum and causes PSyclone to run again.

Written by the indexing model from the issue text.