RFR: 8327839: Crash with unboxing and widening primitive conversion in switch [v2]

[Aggelos Biboudis]

> In cases where the compiler needs to unbox a `long`, `float`, `double` and then run the exactness check, we were getting a crash. While the selector value is always boxed, the type (which controls the execution flow) was not, because the `selectorType` was wrong. This PR addresses this bug.

Aggelos Biboudis has updated the pull request incrementally with one additional commit since the last revision:

  Update test/langtools/tools/javac/patterns/PrimitivePatternsSwitch.java
  
  Co-authored-by: Andrey Turbanov <turbanoff at gmail.com>

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Changes:
  - all: https://git.openjdk.org/jdk/pull/18236/files
  - new: https://git.openjdk.org/jdk/pull/18236/files/ecf909d0..50275918

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18236&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18236&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/18236.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18236/head:pull/18236

PR: https://git.openjdk.org/jdk/pull/18236