[jdk17] RFR: 8269802: javac fails to compile nested pattern matching switches

[Jan Lahoda]

There are two places which where `TransPatterns` is mistakenly not translating a subtree: the statements for non-pattern cases, and the selector. This PR is fixing that by translating the statements and selector.

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Commit messages:
 - Neeed to translate switch selectors for pattern matching switches.
 - 8269802: javac fails to compile nested pattern matching switches

Changes: https://git.openjdk.java.net/jdk17/pull/203/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17&pr=203&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8269802
  Stats: 124 lines in 2 files changed: 123 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk17/pull/203.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17 pull/203/head:pull/203

PR: https://git.openjdk.java.net/jdk17/pull/203