RFR: 8185844: MSCAPI doesn't list aliases correctly

[Weijun Wang]

If a entry is overwritten by another one using the same alias, make sure the old one is removed.

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Commit messages:
 - 8185844: MSCAPI doesn't list aliases correctly

Changes: https://git.openjdk.java.net/jdk/pull/6047/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6047&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8185844
  Stats: 174 lines in 2 files changed: 123 ins; 34 del; 17 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6047.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6047/head:pull/6047

PR: https://git.openjdk.java.net/jdk/pull/6047