RFR: 8289436: Make the redefine timer statistics more accurate

[Tongbao Zhang]

Make the redefine timer statistics more accurate

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Commit messages:
 - 8289436: Make the redefine timer statistics more accurate

Changes: https://git.openjdk.org/jdk/pull/9322/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9322&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8289436
  Stats: 10 lines in 2 files changed: 8 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/9322.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9322/head:pull/9322

PR: https://git.openjdk.org/jdk/pull/9322