This change avoids formatting table entries into a string, only to split
them apart again. The new format is also slightly easier to read and
compare when changes are made to how the tables are organized.
This commit imports update to regexes in `load_properties()`,
d25c39f86568a147f9b7080c25711fb1f98f056a in rust-lang/regex
Does not result in any changes to tables.rs, but could if
published tables are updated in the future.