RFR: 8315869: UseHeavyMonitors not used [v2]

[Coleen Phillimore]

> Please review this trivial change to remove the UseHeavyMonitors develop option, in favor of the now non-experimental LockingMode=LM_MONITOR (0) option.  Tested with tier1 locally.

Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:

  Update option comment.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/15845/files
  - new: https://git.openjdk.org/jdk/pull/15845/files/acecf6f2..5d00c551

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15845&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15845&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/15845.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15845/head:pull/15845

PR: https://git.openjdk.org/jdk/pull/15845