RFR: 1189: Update mapping so the Hotspot Style Guide is reviewed on hotspot-dev

[Magnus Ihse Bursie]

This will add review target list hotspot-dev for doc/hotspot-style and doc/hotspot-unit-tests.

Since there is no exclude mechanism in the mailing list selection, it is not easy to exclude these from the build-dev target. In this case, I think it's okay to cross-post to build-dev (I like to keep track of documentation changes :)) but in the long term I think the mailing list rules should benefit from having an exclusion system to exclude certain subparts of a directory tree (not just in this case).

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

Commit messages:
 - 1189: Update mapping so the Hotspot Style Guide is reviewed on hotspot-dev

Changes: https://git.openjdk.java.net/skara/pull/1230/files
 Webrev: https://webrevs.openjdk.java.net/?repo=skara&pr=1230&range=00
  Issue: https://bugs.openjdk.java.net/browse/SKARA-1189
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/skara/pull/1230.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/1230/head:pull/1230

PR: https://git.openjdk.java.net/skara/pull/1230