RFR: 8339466: Enumerate shared stubs and define static fields and names via declarations [v3]

[Andrew Dinn]

> Systematize handling of SharedRuntime stubs. Generate enum ids, static fields and names from declarations using template macros. Systematically reference stubs and stub names using ids.

Andrew Dinn has updated the pull request incrementally with three additional commits since the last revision:

 - riscv review feedback
 - fix enum class name
 - initial review feedback

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Changes:
  - all: https://git.openjdk.org/jdk/pull/20832/files
  - new: https://git.openjdk.org/jdk/pull/20832/files/b5220093..681f8cb7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20832&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20832&range=01-02

  Stats: 256 lines in 11 files changed: 25 ins; 84 del; 147 mod
  Patch: https://git.openjdk.org/jdk/pull/20832.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20832/head:pull/20832

PR: https://git.openjdk.org/jdk/pull/20832