The `jar` and `jmod` tools support the command line option `--hash-modules` to compute and record the hashes of modules that depend upon directly or indirectly on a module in a modular JAR or JMOD file. The generation of this hash is changed in this release so that it is reproducible, and more specifically, it is no longer dependent on the ordering of entries in the JAR or JMOD file or the timestamps of entries.

Modular JAR or JMOD files that have recorded hashes computed with JDK 14 or older will now be rejected by the `jlink` tool. The `jar` and `jmod` tools must be re-run to compute and record new hashes.