RFR: 8368938: ObjectWaiter::badObjectWaiterPtr could be static

[Francesco Andreuzzi]

There's apparently no reason against having the symbol shared for all instances. This saves a byte from the definition of `ObjectWaiter`.

Passes tier1 and tier2 (fastdebug).

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Commit messages:
 - make static

Changes: https://git.openjdk.org/jdk/pull/27571/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27571&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8368938
  Stats: 3 lines in 2 files changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/27571.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27571/head:pull/27571

PR: https://git.openjdk.org/jdk/pull/27571