RFR: JDK-8319300: Remove unused methods in WorkArounds and Utils [v2]

[Hannes Wallnöfer]

> Please review a simple removal of unused methods in `WorkArounds` and `Utils`. 
> 
> `Utils.findClass(Element,String)` was the principal entry point of this cluster of methods. It was last used by the `ThrowsTaglet` `inherit` method, but that code was removed in JDK-8295277.

Hannes Wallnöfer has updated the pull request incrementally with one additional commit since the last revision:

  Update copyright header

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Changes:
  - all: https://git.openjdk.org/jdk/pull/16472/files
  - new: https://git.openjdk.org/jdk/pull/16472/files/812785a7..20529e26

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16472&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16472&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/16472.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16472/head:pull/16472

PR: https://git.openjdk.org/jdk/pull/16472