julia

c4eeabf2 - `AnnotatedString`: add concrete type asserts to `isvalid`, `ncodeunits` (#57607)

`AnnotatedString`: add concrete type asserts to `isvalid`, `ncodeunits` (#57607) The type assertions are valid according to the doc strings of these two functions in the case of `AbstractString`. Should prevent some invalidation on loading user code. Fixes #57606