RFR: 8343188: Investigate ways to simplify MemorySegment::ofBuffer [v5]

[Per Minborg]

> This PR proposes to improve `MemorySegment::ofBuffer` making it more amenable to inlining and generally improving performance.
> 
> Testing successfully on tier1-3

Per Minborg has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 12 additional commits since the last revision:

 - Update comments
 - Merge branch 'master' into optimize-ms-ofbuffer
 - Rename method
 - Rename method
 - Fix issue in scaleFactor()
 - Update from comments and add benchmark
 - Remove switch rake and move factories to Buffer impls
 - Clean up generated code
 - Revert changes
 - Remove unused imports
 - ... and 2 more: https://git.openjdk.org/jdk/compare/e889323e...e6b03e8b

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/21764/files
  - new: https://git.openjdk.org/jdk/pull/21764/files/b3e4eb60..e6b03e8b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21764&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21764&range=03-04

  Stats: 55223 lines in 1062 files changed: 12369 ins; 40472 del; 2382 mod
  Patch: https://git.openjdk.org/jdk/pull/21764.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21764/head:pull/21764

PR: https://git.openjdk.org/jdk/pull/21764