RFR: 8267396: Avoid recording "pc" in unhandled oops detector for better performance

[Aleksey Shipilev]

See the rationale in the bug.

Additional testing:
 - [x] Known slow test with `-XX:+CheckUnhandledOops`
 - [ ] tier1 with `-XX:+CheckUnhandledOops`

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Commit messages:
 - 8267396: Avoid recording "pc" in unhandled oops detector for better performance

Changes: https://git.openjdk.java.net/jdk/pull/4114/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4114&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8267396
  Stats: 11 lines in 3 files changed: 0 ins; 3 del; 8 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4114.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4114/head:pull/4114

PR: https://git.openjdk.java.net/jdk/pull/4114