RFR: 8365191: Cleanup after removing LockingMode related code

[Fredrik Bredberg]

This is a general cleanup after removing `LockingMode` related code.
It's a sub-task of [JDK-8344261](https://bugs.openjdk.org/browse/JDK-8344261).
It includes:
- Removing asserts that are no longer necessary, since we removed legacy locking and monitor locking.
- Removing or rewriting comments, arguments or functions that are related to displaced headers.
- Remove "always true" parameter from `MonitorExitStub`.
- Re-type/name metadata in `BasicLock`.

Tier1-5 passes okay on supported platforms.

All other platforms (arm, ppc, riscv and s390) has been sanity checked using Qemu.

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Commit messages:
 - Merge branch 'master' into 8365191_lockingmode_cleanup
 - 8365191: Cleanup after removing LockingMode related code

Changes: https://git.openjdk.org/jdk/pull/27448/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27448&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8365191
  Stats: 168 lines in 34 files changed: 2 ins; 43 del; 123 mod
  Patch: https://git.openjdk.org/jdk/pull/27448.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27448/head:pull/27448

PR: https://git.openjdk.org/jdk/pull/27448