RFR: 8264536: Building OpenJFX on Apple AARCH64 not possible

[Johan Vos]

don't bail when building on Apple M1 systems
Fix for JDK-8264536

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Commit messages:
 - don't bail when building on Apple M1 systems

Changes: https://git.openjdk.java.net/jfx/pull/451/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=451&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8264536
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jfx/pull/451.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/451/head:pull/451

PR: https://git.openjdk.java.net/jfx/pull/451