[jdk11u-dev] RFR: 8219986: Change to Xcode 10.1 for building on Macosx at Oracle

[Christoph Langer]

Backport of JDK-8219986

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Commit messages:
 - Backport 53adab6857492905246c024b80a27bb989a996e3

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/557/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=557&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8219986
  Stats: 169 lines in 3 files changed: 1 ins; 164 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/557.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/557/head:pull/557

PR: https://git.openjdk.java.net/jdk11u-dev/pull/557