[jdk21u-dev] RFR: 8292955: Collections.checkedMap Map.merge does not properly check key and value

[Daniel Hu]

Clean backport. This ensures Collections.checkedMap Map.merge fails when key value types don't match. Affected test on linux x64 and GHA passes.

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

Commit messages:
 - Backport b5e1615c0084538f2161fe9b56748d188983e972

Changes: https://git.openjdk.org/jdk21u-dev/pull/1730/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=1730&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8292955
  Stats: 12 lines in 2 files changed: 9 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/1730.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/1730/head:pull/1730

PR: https://git.openjdk.org/jdk21u-dev/pull/1730