RFR: 8271931: Make AbortVMOnVMOperationTimeout more resilient to OS scheduling [v2]

[Albert Mingkun Yang]

> Perform VM-op timeout also on the VM thread. If a VM-op is stuck, the existing watcher-thread based machinery will kick in and detect it.
> 
> Test: tier1

Albert Mingkun Yang has updated the pull request incrementally with one additional commit since the last revision:

  review

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5016/files
  - new: https://git.openjdk.java.net/jdk/pull/5016/files/91127dac..efe46dcc

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5016&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5016&range=00-01

  Stats: 31 lines in 2 files changed: 14 ins; 8 del; 9 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5016.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5016/head:pull/5016

PR: https://git.openjdk.java.net/jdk/pull/5016