RFR: 8057113: (fs) Path should have a method to obtain the filename extension [v18]

[Mark Reinhold]

On Mon, 1 Aug 2022 21:54:22 GMT, Brian Burkhalter <bpb at openjdk.org> wrote:

>> Resurrection of the proposal to add a method to obtain the filename extension originated in PR [2319](https://github.com/openjdk/jdk/pull/2319).
>
> Brian Burkhalter has updated the pull request incrementally with one additional commit since the last revision:
> 
>   8057113: Remove API note

The most surprising thing would be to consider `.foo` to have the extension `foo`, which would make it impossible to treat `.foo` together with `.foo.log` in a sensible way.

Multiple leading period characters are a corner case of a corner case.

-------------

PR: https://git.openjdk.org/jdk/pull/8066