RFR: 8343767: Enumerate StubGen blobs, stubs and entries and generate code from declarations [v2]

[Andrew Dinn]

> Implementation of JDK-8343767

Andrew Dinn has updated the pull request incrementally with one additional commit since the last revision:

  fix comments and remove unused stubid on riscv

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Changes:
  - all: https://git.openjdk.org/jdk/pull/21957/files
  - new: https://git.openjdk.org/jdk/pull/21957/files/1c0766a6..b0680822

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21957&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21957&range=00-01

  Stats: 24 lines in 2 files changed: 10 ins; 3 del; 11 mod
  Patch: https://git.openjdk.org/jdk/pull/21957.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21957/head:pull/21957

PR: https://git.openjdk.org/jdk/pull/21957