RFR: JDK-8290011: IGV: Remove dead code and cleanup [v4]

[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:

  Update src/utils/IdealGraphVisualizer/View/src/main/java/com/sun/hotspot/igv/view/EditorTopComponent.java
  
  remove whitespace
  
  Co-authored-by: Christian Hagedorn <christian.hagedorn at oracle.com>

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Changes:
  - all: https://git.openjdk.org/jdk/pull/10197/files
  - new: https://git.openjdk.org/jdk/pull/10197/files/10c47a1e..23ddbf98

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10197&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10197&range=02-03

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 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