Merge branch 'jk/no-more-self-assignment'

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