[jdk11u-dev] RFR: 8364660: ClassVerifier::ends_in_athrow() should be removed

[Andrew John Hughes]

This backport removes the `ends_in_athrow` check which has been obsoleted by [JDK-8302497](https://bugs.openjdk.org/browse/JDK-83024970), specifically:

"There is no way to perform a return instruction given that type state, so the handler would have to throw another exception (or loop forever). In fact, it's not even possible to express a handler with that type state, because there is no way for a stack frame, as expressed by the StackMapTable attribute ([4.7.4](https://docs.oracle.com/javase/specs/jvms/se22/html/jvms-4.html#jvms-4.7.4)), to carry flagThisUninit without any accompanying use of type uninitializedThis."  [0]

The backport is mostly clean, with the following exceptions:

1. The removed code in `verifier.cpp` used `log_info` and the `Info` type rather than `log_debug` and `Debug`. (no [JDK-8234656](https://bugs.openjdk.org/browse/JDk-8234656))
2. The copyright header of `verifier.hpp` was older in 11u.

[0] https://cr.openjdk.org/~dlsmith/8302497/8302497-20231218/specs/invokespecial-verification-jvms.html

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Commit messages:
 - Backport 3f884a976a1cfc8ffa8a9f80d682a108ec4f58a3

Changes: https://git.openjdk.org/jdk11u-dev/pull/3134/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=3134&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8364660
  Stats: 241 lines in 2 files changed: 0 ins; 240 del; 1 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/3134.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/3134/head:pull/3134

PR: https://git.openjdk.org/jdk11u-dev/pull/3134