RFR: 8289129: [BACKOUT] JDK-8287281 adjust guarantee in Handshake::execute for the case of target thread being current

[Daniel D. Daugherty]

This reverts commit 9dc9a64fa453d8afc90871e9663a0ccc46212f64.

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Commit messages:
 - 8289129: [BACKOUT] JDK-8287281 adjust guarantee in Handshake::execute for the case of target thread being current

Changes: https://git.openjdk.org/jdk/pull/9277/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9277&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8289129
  Stats: 30 lines in 3 files changed: 14 ins; 8 del; 8 mod
  Patch: https://git.openjdk.org/jdk/pull/9277.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9277/head:pull/9277

PR: https://git.openjdk.org/jdk/pull/9277