incremental psyclone

[bblay]

Todo: Needs definition. What are the things which, when changed, must trigger reprocessing of a file?

• Obviously the preprocessed x90 is one.
• There can be multiple "kernel root" folders too. Should we rebuild if anything in those changes, or can/should we parse and discover just the files?
• Anything else?

Something's been updated in LFRic since we pinned the version, too. I believe it now uses big X90s and little x90s to differentiate preprocessed source.

"...the basic rule is that PSyclone needs to be re-run if the algorithm (.x90) file, the kernels (included by the .x90) or the transformation script change."

"The transformation script is passed to PSyclone as an argument. That script is a python script..."