RFR: 8286858: Remove dead code in sun.reflect.misc.MethodUtil

[Andrey Turbanov]

They are unused and leftover since JDK 7.  It's good to remove them.

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Commit messages:
 - [PATCH] Remove unused code in sun.reflect.misc.MethodUtil

Changes: https://git.openjdk.java.net/jdk/pull/8715/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8715&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8286858
  Stats: 179 lines in 1 file changed: 4 ins; 170 del; 5 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8715.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8715/head:pull/8715

PR: https://git.openjdk.java.net/jdk/pull/8715