[lworld] RFR: 8310023: [lworld] Implement alternative fast-locking scheme in Valhalla [v2]

[Coleen Phillimore]

> I don't see anything missing for implementing the test for inline types for lightweight locking.  The only thing broken seems to be JNI monitorenter should throw IdentityException.  I added some comments and asserts when I figured out the interpreter and c1/c2 don't get to ObjectSynchronizer::enter.
> Tested with tier1 with LM_LIGHTWEIGHT as the default.

Coleen Phillimore has refreshed the contents of this pull request, and previous commits have been removed. Incremental views are not available. The pull request now contains one commit:

  8310023: [lworld] Implement alternative fast-locking scheme in Valhalla

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Changes:
  - all: https://git.openjdk.org/valhalla/pull/1158/files
  - new: https://git.openjdk.org/valhalla/pull/1158/files/93e487e7..c889826e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1158&range=01
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1158&range=00-01

  Stats: 25 lines in 2 files changed: 0 ins; 15 del; 10 mod
  Patch: https://git.openjdk.org/valhalla/pull/1158.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1158/head:pull/1158

PR: https://git.openjdk.org/valhalla/pull/1158