git: openjdk/jfx: master: 8251858: Update to Xcode 11.3.1

[Kevin Rushforth]

Changeset: 87ad57f1
Author:    Kevin Rushforth <kcr at openjdk.org>
Date:      2020-08-29 12:05:43 +0000
URL:       https://git.openjdk.java.net/jfx/commit/87ad57f1

8251858: Update to Xcode 11.3.1

Reviewed-by: jvos, arapte

! build.properties
! buildSrc/mac.gradle