[PATCH] 8385738: Javadoc does not produce reproducible output due to the snippet...

[PATCH] 8385738: Javadoc does not produce reproducible output due to the snippet ids The top level type generation order is not deterministic due to the directory listing being non-deterministic. Snippet ids are monotonically incremented during the javadoc run. This means that the generated snippet ids are not reproducible. This PR changes Set to the Map so that each page uses a separate snippet id counter.

Bug: https://bugs.openjdk.org/browse/JDK-8385738
Reviewed-by: nbenalla
Gbp-Pq: Name jdk-8385738.diff