RFR: 8339849: Enumerate opto and C1 stubs, generate enums, names, fields and generator calls [v2]

[Andrew Dinn]

> Systematize handling of Opto and C1 stubs. Generate enum ids, static fields, stub/blob names and generator code from declarations using template macros as previously done with Shared stubs. Systematically reference stubs and stub names using ids.

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

 - Answer review feedback
 - remove commented out old code

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/20936/files
  - new: https://git.openjdk.org/jdk/pull/20936/files/f1f7fc28..b2e81b04

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20936&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20936&range=00-01

  Stats: 131 lines in 7 files changed: 20 ins; 37 del; 74 mod
  Patch: https://git.openjdk.org/jdk/pull/20936.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20936/head:pull/20936

PR: https://git.openjdk.org/jdk/pull/20936