RFR: 8338979: Avoid bootstrapped switches in the classfile API [v2]

[Claes Redestad]

> Noticed these on a few startup tests in code generating proxies. Desugaring switch expressions reduce risk of bootstrap circularity from any future changes to switch bootstrapping (which itself depends on the classfile API). It's also a tiny improvement to startup performance.

Claes Redestad has updated the pull request incrementally with one additional commit since the last revision:

  Copyright

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Changes:
  - all: https://git.openjdk.org/jdk/pull/20714/files
  - new: https://git.openjdk.org/jdk/pull/20714/files/43429cc0..8244c4a2

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20714&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20714&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/20714.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20714/head:pull/20714

PR: https://git.openjdk.org/jdk/pull/20714