RFR: 8350118: Simplify the layout access VarHandle

[Chen Liang]

Simplify the layout access var handles to be direct in some common cases. Also made `VarHandle::isAccessModeSupported` report if an access mode is supported for a VH.

Reduces the instructions to execute this code in a simple main by 47%:

long[] arr = new long[8];
var ms = MemorySegment.ofArray(arr);
ms.setAtIndex(ValueLayout.JAVA_BYTE, 12, (byte) 3);


Main overheads in FFM are identified to be:
1. Eager initialization of direct MethodHandle; can be CDS archived
2. MH combinator forms via LambdaFormEditor, not cached right now and always have large overhead

Still need other measures to deal with common user patterns of `MethodHandles.insertCoordinates(vh, 1, 0L)` which currently is still very slow.

Tests: tier 1-3 running

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

Commit messages:
 - More cleanup
 - Merge branch 'master' of https://github.com/openjdk/jdk into feature/ffm-vh-inline
 - Make sure the form impl class is initialized
 - Reduce MT initialization work
 - MH linkToStatic stall
 - Merge branch 'master' of https://github.com/openjdk/jdk into feature/ffm-vh-inline
 - Merge branch 'master' of https://github.com/openjdk/jdk into feature/ffm-vh-inline
 - Enhance cache for basic value layouts
 - More stuff
 - VH inline stuff stage

Changes: https://git.openjdk.org/jdk/pull/23720/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23720&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8350118
  Stats: 1869 lines in 16 files changed: 1056 ins; 215 del; 598 mod
  Patch: https://git.openjdk.org/jdk/pull/23720.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23720/head:pull/23720

PR: https://git.openjdk.org/jdk/pull/23720