RFR: JDK-8290011: IGV: Remove dead code and cleanup [v16]

[Tobias Holenstein]

> Remove dead code from the IGV code base. There are many unused or redundant functions in the code

Tobias Holenstein has updated the pull request incrementally with one additional commit since the last revision:

  cleanup after merger with master

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/10197/files
  - new: https://git.openjdk.org/jdk/pull/10197/files/7faec1a5..a7271acf

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10197&range=15
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10197&range=14-15

  Stats: 340 lines in 13 files changed: 263 ins; 28 del; 49 mod
  Patch: https://git.openjdk.org/jdk/pull/10197.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10197/head:pull/10197

PR: https://git.openjdk.org/jdk/pull/10197