[lworld] RFR: 8348607: [lworld] Calls to Unsafe.getValue() / Unsafe.putValue() must be updated [v3]

[Chen Liang]

> Core libraries counterpart of #1336.
> 
> This requires MemberName to fetch more information in initialization. A new int high flag field is added, in anticipation to a merger with the regular int flag field in the future. Currently, directly migrating the flags field to long is too impactful to the whole codebase.
> 
> Also 8348680 is addressed as well; it's some minor updates to make the null checks specific to references VH.
> 
> Testing: test/jdk/java/lang/invoke

Chen Liang has updated the pull request incrementally with one additional commit since the last revision:

  Review remarks and other adjustments
  
  Value in template -> FlatValue
  Update flat encoding in MemberName, remove high flags for now
  layout 0 means non-flat reliably
  Problemlist TestIntrinsics, issue created

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Changes:
  - all: https://git.openjdk.org/valhalla/pull/1340/files
  - new: https://git.openjdk.org/valhalla/pull/1340/files/a06cb9dc..87a21b8c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1340&range=02
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1340&range=01-02

  Stats: 171 lines in 11 files changed: 13 ins; 27 del; 131 mod
  Patch: https://git.openjdk.org/valhalla/pull/1340.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1340/head:pull/1340

PR: https://git.openjdk.org/valhalla/pull/1340