RFR: 8274811: Remove superfluous use of boxing in java.base

[Andrey Turbanov]

Usages of primitive types should be preferred and makes code easier to read.
Similar cleanups:
1. [JDK-8273168](https://bugs.openjdk.java.net/browse/JDK-8273168) java.desktop
2. [JDK-8274234](https://bugs.openjdk.java.net/browse/JDK-8274234) java.sql.rowset

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Commit messages:
 - [PATCH] Remove superfluous use of boxing in java.base
 - [PATCH] Remove superfluous use of boxing in java.* modules
 - [PATCH] Remove superfluous use of boxing in java.* modules

Changes: https://git.openjdk.java.net/jdk/pull/5481/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5481&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8274811
  Stats: 11 lines in 4 files changed: 0 ins; 0 del; 11 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5481.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5481/head:pull/5481

PR: https://git.openjdk.java.net/jdk/pull/5481