Revert "Rename unicode_combining_table to unicode_width_table"
This reverts commit
eb0d0d2c7300c9c5c22b35975c11265aa4becc84.
After I had committed
eb0d0d2c7 and
78ab944cd, I decided to add
a sanity check for a "can't happen" scenario just to be cautious.
It turned out that it already happened in the official Unicode source
data, namely that a character can be both wide and a combining
character. This fact renders the aforementioned commits unnecessary,
so revert both of them.
Discussion: https://www.postgresql.org/message-id/CAFBsxsH5ejH4-1xaTLpSK8vWoK1m6fA1JBtTM6jmBsLfmDki1g%40mail.gmail.com