RFR: 8283864: Clean up DocFinder and friends [v2]

[Pavel Rappo]

> A clean-up to facilitate more clean-up in the future.

Pavel Rappo has updated the pull request incrementally with one additional commit since the last revision:

  Address feedback

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8229/files
  - new: https://git.openjdk.java.net/jdk/pull/8229/files/50c33364..7bc2fe39

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8229&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8229&range=00-01

  Stats: 6 lines in 2 files changed: 0 ins; 0 del; 6 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8229.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8229/head:pull/8229

PR: https://git.openjdk.java.net/jdk/pull/8229