checking but can happen for incorrect formats parsed via ParsedFormat::New.
Specifically, if a user were to add length modifiers with 'v', for example the
incorrect format string "%hv", the ParsedFormat would incorrectly be allowed.

PiperOrigin-RevId: 480183817
Change-Id: I8510c13189fdf807cdaa7f2e1b7ed9fba2aaefb9