julia

7f9d33d2 - strings: type assert in the generic `nextind`, `prevind` methods (#57608)

strings: type assert in the generic `nextind`, `prevind` methods (#57608) The type assertions are valid according to the doc strings of these functions in the case of `AbstractString`. Should prevent some invalidation on loading user code. Fixes #57605 (cherry picked from commit 6c9c336d2acc71ed740b0cc470c0b76bbbda136c)