Mark unhittable code

The earlier tests that _region_dialing_from_matches_number
mean that we shouldn't get missing metadata.

Prep for 7.7.5 release

buildmetadata: drop unused fill_na param

Prep for 7.7.3 release

Prep for 7.7.3 release

Prep for 7.7.2 release

Prep for 7.7.2 release

Merge code changes from upstream 7.7.1

Also sync shortnumberinfo.py more closely with upstream
ShortNumberInfo.java and friends (cf. commit 2f3fd02).

Merge code changes from upstream 7.7.1

Also sync shortnumberinfo.py more closely with upstream
ShortNumberInfo.java and friends (cf. commit 2f3fd02).

Don't propagate the special -1 value for possible_length