Merge branch 'ma/leakplugs'

Memory leaks in various codepaths have been plugged. * ma/leakplugs: pack-bitmap[-write]: use `object_array_clear()`, don't leak object_array: add and use `object_array_pop()` object_array: use `object_array_clear()`, not `free()` leak_pending: use `object_array_clear()`, not `free()` commit: fix memory leak in `reduce_heads()` builtin/commit: fix memory leak in `prepare_index()`