<AWT Dev> RFR: 8273168: Remove superfluous use of boxing in java.desktop

[Andrey Turbanov]

parseInt/parseLong/parseShort/parseByte/parseFloat should be preferred, as they return primitives. While valueOf returns boxed object.

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Commit messages:
 - [PATCH] Cleanup redundant boxing in java.desktop module

Changes: https://git.openjdk.java.net/jdk/pull/5313/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5313&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8273168
  Stats: 18 lines in 7 files changed: 0 ins; 1 del; 17 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5313.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5313/head:pull/5313

PR: https://git.openjdk.java.net/jdk/pull/5313