Recompile when Prism headers change

[eregon]

• See Recompile when config.yml changes #3932 (comment)

[Earlopain]

I think your previous PR can be reverted, since this covers that? I can check that tomorrow if you don't want to

[eregon]

Right, all *.c and *.h should be tracked, and if config.yml changes without changing those it shouldn't matter for the extension, i.e. it doesn't need to be recompiled then.
I'll push a revert of that commit.

[eregon]

Done.
FWIW changing config.yml by e.g. adding a comment still recompiles everything most likely because the generated .h files are still regenerated (Prism::Template.render writes unconditionally) and get a new mtime. That's fine though (and not a common use case, most changes to config.yml would change .h/.c files).

[kddnewton]

Oh nice that seems cleaner