[jdk16] RFR: 8258662: JDK 17ea: Crash compiling instanceof check involving sealed interface

[Guoxiong Li]

Hi all,

The method `Types.isCastable` uses method `Types.areDisjoint` to do some check. But `Types.isCastable` doesn't check the type of the parameter before invoking method `Types.areDisjoint`. This patch adds the corresponding check and add a test case.

The original patch is in https://github.com/openjdk/jdk/pull/1849.

Thank you for taking the time to review.

Best Regards.

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Commit messages:
 - 8258662: JDK 17ea: Crash compiling instanceof check involving sealed interface

Changes: https://git.openjdk.java.net/jdk16/pull/63/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk16&pr=63&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8258662
  Stats: 78 lines in 2 files changed: 77 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk16/pull/63.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk16 pull/63/head:pull/63

PR: https://git.openjdk.java.net/jdk16/pull/63