RFR: 8284672: Collapse identical catch branches in java.desktop

[Andrey Turbanov]

Let's take advantage of Java 7 language feature - "Catching Multiple Exception Types".
It simplifies code. Reduces duplication.
Found by IntelliJ IDEA inspection Identical 'catch' branches in 'try' statement

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Commit messages:
 - [PATCH] Collapse identical catch branches in java.desktop

Changes: https://git.openjdk.java.net/jdk/pull/8154/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8154&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8284672
  Stats: 300 lines in 45 files changed: 2 ins; 170 del; 128 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8154.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8154/head:pull/8154

PR: https://git.openjdk.java.net/jdk/pull/8154