[master] RFR: Lilliput om world [v2]

[Coleen Phillimore]

> Added a diagnostic option UseObjectMonitorTable to maintain performance of LM_LIGHTWEIGHT locking which is now defaulted to on in mainline.
> 
> Incorporated Axel's patch to support other platforms with UseObjectMonitorTable (branch to slow path).
> 
> Tested tier 1-4 on x86.  Fails both versions of this test, but not locally:  runtime/cds/TestDefaultArchiveLoading.java.
> 
> tier1 aarch64 in progress.

Coleen Phillimore has updated the pull request incrementally with seven additional commits since the last revision:

 - Merge pull request #1 from xmas92/lilliput-om-world
   
   Review Comments
 - Remove OM_OFFSET_NO_MONITOR_VALUE_TAG changes
 - Remove OMUseC2Cache
 - aarch64: Make C2 unchanged when !UseObjectMonitorTable
 - x86: Make C2 unchanged when !UseObjectMonitorTable
 - Fix OM_OFFSET_NO_MONITOR_VALUE_TAG
 - Review Comments

-------------

Changes:
  - all: https://git.openjdk.org/lilliput/pull/181/files
  - new: https://git.openjdk.org/lilliput/pull/181/files/64e54ea4..3e74a698

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=lilliput&pr=181&range=01
 - incr: https://webrevs.openjdk.org/?repo=lilliput&pr=181&range=00-01

  Stats: 275 lines in 13 files changed: 96 ins; 76 del; 103 mod
  Patch: https://git.openjdk.org/lilliput/pull/181.diff
  Fetch: git fetch https://git.openjdk.org/lilliput.git pull/181/head:pull/181

PR: https://git.openjdk.org/lilliput/pull/181