RFR: 8275718: Relax memory constraint on exception counter updates

[Zhengyu Gu]

This is another instance of counter updates that only need atomic guarantee.

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Commit messages:
 - v0

Changes: https://git.openjdk.java.net/jdk/pull/6065/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6065&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8275718
  Stats: 5 lines in 1 file changed: 0 ins; 0 del; 5 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6065.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6065/head:pull/6065

PR: https://git.openjdk.java.net/jdk/pull/6065