RFR: 8314578: Non-verifiable code is emitted when two guards declare pattern variables in colon-switch

[Aggelos Biboudis]

In the following example while the case pattern does not introduce binding variable, the guard does. `hasBindings` has been updated accordingly to accept any trees and check them if they contain a `visitBindingPattern`. Not only `JCPattern`'s.


static void test(Object o) {
    switch (o) {
      case R1() when o instanceof String s:
      case R2() when o instanceof Integer i:
        System.out.println("hello: " + i);
        break;
      default:
        break;
    }
  }

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

Commit messages:
 - 8314578: Non-verifiable code is emitted when two guards declare pattern variables in colon-switch

Changes: https://git.openjdk.org/jdk/pull/15630/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15630&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8314578
  Stats: 41 lines in 3 files changed: 38 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/15630.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15630/head:pull/15630

PR: https://git.openjdk.org/jdk/pull/15630