RFR: 8263322: Deadlock when calling Application.launch in the FXThread after Platform.startup [v5]

[Florian Kirmaier]

> Fixing deadlock when calling Application.launch in the FXThread after Platform.startup

Florian Kirmaier has updated the pull request incrementally with one additional commit since the last revision:

  JDK-8263322
  fixed the copyright headers, based on codereview

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Changes:
  - all: https://git.openjdk.java.net/jfx/pull/421/files
  - new: https://git.openjdk.java.net/jfx/pull/421/files/c16b6067..145ae592

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jfx&pr=421&range=04
 - incr: https://webrevs.openjdk.java.net/?repo=jfx&pr=421&range=03-04

  Stats: 3 lines in 3 files changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/jfx/pull/421.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/421/head:pull/421

PR: https://git.openjdk.java.net/jfx/pull/421