RFR: 8319615: IGV incomplete gitignore [v2]

[Daniel Lundén]

> This changeset adds a number of IGV-generated files to the IGV `.gitignore`.
> 
> ### Testing
> No testing as there are no code changes.

Daniel Lundén has updated the pull request incrementally with one additional commit since the last revision:

  Remove empty line

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/16538/files
  - new: https://git.openjdk.org/jdk/pull/16538/files/116379b8..9495df03

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16538&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16538&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/16538.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16538/head:pull/16538

PR: https://git.openjdk.org/jdk/pull/16538