RFR: 8316967: Correct the scope of vmtimer in UnregisteredClasses::load_class [v4]

[Calvin Cheung]

> Simple fix for removing the vmtimer from `UnregisteredClasses::load_class` and the corresponding `PerfClassTraceTime` constructor.
> 
> Passed tier1 testing.
> --------------------
> Update: correct the scope of the vmtimer instead of removing it.

Calvin Cheung has updated the pull request incrementally with one additional commit since the last revision:

  remove _perf_sys_class_lookup_time

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/16046/files
  - new: https://git.openjdk.org/jdk/pull/16046/files/fd2a078b..56e35c02

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16046&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16046&range=02-03

  Stats: 3 lines in 2 files changed: 0 ins; 3 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/16046.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16046/head:pull/16046

PR: https://git.openjdk.org/jdk/pull/16046