RFR: 8282019: Unused static fields DEGREES_TO_RADIANS, RADIANS_TO_DEGREES in StrictMath

[Andrey Turbanov]

Couple of fields in StrictMath are unused since [JDK-8244146](https://bugs.openjdk.java.net/browse/JDK-8244146).
Also I fixed incorrect javadoc for private method. Looks like typo in [JDK-6282196](https://bugs.openjdk.java.net/browse/JDK-6282196)

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Commit messages:
 - [PATCH] Remove unused static fields 'DEGREES_TO_RADIANS', RADIANS_TO_DEGREES in StrictMath

Changes: https://git.openjdk.java.net/jdk/pull/7495/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7495&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8282019
  Stats: 17 lines in 1 file changed: 0 ins; 13 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7495.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7495/head:pull/7495

PR: https://git.openjdk.java.net/jdk/pull/7495