RFR: JDK-8290011: IGV: Remove dead code and cleanup [v8]

[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:

  style update 2

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Changes:
  - all: https://git.openjdk.org/jdk/pull/10197/files
  - new: https://git.openjdk.org/jdk/pull/10197/files/419db83c..127e18d7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10197&range=07
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10197&range=06-07

  Stats: 197 lines in 17 files changed: 2 ins; 120 del; 75 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