RFR: 8210547: [Linux] Uncontrolled framerate [v3]

[notzed]

> As discussed on the mailing list.
> 
> OpenGL requires an explicit glFinish() to synchronise with the video refresh.  The current usage is incorrect and against the specification.  This patch calls glFinish() after all windows have been drawn following a pulse.

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

  Merge part of #1929, call glXSwapIntervalEXT in preference to glXSwapIntervalSGI if available.

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Changes:
  - all: https://git.openjdk.org/jfx/pull/1981/files
  - new: https://git.openjdk.org/jfx/pull/1981/files/293c5712..448a4f25

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1981&range=02
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1981&range=01-02

  Stats: 21 lines in 3 files changed: 16 ins; 1 del; 4 mod
  Patch: https://git.openjdk.org/jfx/pull/1981.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1981/head:pull/1981

PR: https://git.openjdk.org/jfx/pull/1981