This reverts commit f09ab8889148c406551dea1643966e3331fde4aa, reversing
changes made to effc761e0ee4ea7ffb77f275b5ed650a7098d6f8.
This is being temporarily reverted to make it easier to release an
urgent fix for v10.15.1.
* Increase likelyhood of valid method signatures being returned by getMethodData
* Update coverage
* Update coverage
* Update coverage
* add a migration to clear knownMethodData
* Small typo changes
Co-authored-by: Alex <adonesky@gmail.com>