RFR: 8290062: Remove nmethodLocker for nmethods on-stack

[Axel Boldt-Christmas]

8290062: Remove nmethodLocker for nmethods on-stack

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

Commit messages:
 - 8290062: Remove nmethodLocker for nmethods on-stack

Changes: https://git.openjdk.org/jdk/pull/9444/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9444&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8290062
  Stats: 11 lines in 1 file changed: 0 ins; 11 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/9444.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9444/head:pull/9444

PR: https://git.openjdk.org/jdk/pull/9444