RFR: 8283402: Update to gcc 11.2 on Linux

[Kevin Rushforth]

This patch updates the compiler to gcc 10.3 on Linux, in order to match JDK 17 -- see [JDK-8283057](https://bugs.openjdk.java.net/browse/JDK-8283057).

I ran a full build and test, including media and WebKit.

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Commit messages:
 - 8283402: Update to gcc 11.2 on Linux

Changes: https://git.openjdk.java.net/jfx/pull/761/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=761&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8283402
  Stats: 6 lines in 3 files changed: 0 ins; 0 del; 6 mod
  Patch: https://git.openjdk.java.net/jfx/pull/761.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/761/head:pull/761

PR: https://git.openjdk.java.net/jfx/pull/761