Summary:
Ref T1191. Test that MySQL's rules match those of `phutil_is_utf8_with_only_bmp_characters()`:
- Build a string with //every// character that we consider to be a BMP character.
- Write it into MySQL.
- Read it back out.
- Make sure MySQL didn't truncate it.
Test Plan: Ran unit test. This test runs pretty quickly (50ms), the string with every character isn't all that enormous.
Reviewers: btrahan, arice
Reviewed By: arice
CC: chad, arice, aran
Maniphest Tasks: T1191
Differential Revision: https://secure.phabricator.com/D8314