This started as a topic to reduce "type var = var" self assignment
tricks that were used to squelch "variable used uninitialized perhaps?"
warning from some compilers, but resulted in rewriting logic with
a version that is simpler and easier to understand for humans.
* jk/no-more-self-assignment:
match-trees: simplify score_trees() using tree_entry()
submodule: clarify logic in show_submodule_summary