Adding logic to handle CCEs and NPEs (the latter cannot logically occur as CHM does not support null keys) as per [AbstractMap::equals](https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/util/AbstractMap.java#L474)
------------- Commit messages: - Addressing 8372256 by catching CCE and NPE during invocation to Map::get in CHM::equals Changes: https://git.openjdk.org/jdk/pull/28453/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28453&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8372256 Stats: 32 lines in 2 files changed: 27 ins; 0 del; 5 mod Patch: https://git.openjdk.org/jdk/pull/28453.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/28453/head:pull/28453 PR: https://git.openjdk.org/jdk/pull/28453
