[lworld] RFR: 8350509: [lworld] Test MHZeroValue is obsolete

[Roger Riggs]

Remove MHZeroValue.java, it is obsolete since the defaultValue concept was removed.

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

Commit messages:
 - 8350509: [lworld] Test MHZeroValue is obsolete

Changes: https://git.openjdk.org/valhalla/pull/1375/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1375&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8350509
  Stats: 92 lines in 1 file changed: 0 ins; 92 del; 0 mod
  Patch: https://git.openjdk.org/valhalla/pull/1375.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1375/head:pull/1375

PR: https://git.openjdk.org/valhalla/pull/1375