[8u] RFR: 8267545: [8u] Enable Xcode 12 builds on macOS

[Hohensee, Paul]

This is the last patch in the series that will enable Xcode 12 builds of 8u. The 8u build system is sufficiently different from later versions that backports beyond what have already been done are unrealistic.

JBS: https://bugs.openjdk.java.net/browse/JDK-8267545
root webrev: https://cr.openjdk.java.net/~phh/8267545/webrev.8u.root.03/
jdk webrev: https://cr.openjdk.java.net/~phh/8267545/webrev.8u.jdk.02/
hotspot webrev: https://cr.openjdk.java.net/~phh/8267545/webrev.8u.hotspot.01/

As detailed in the JBS issue, these are a merge/update by Ben Taylor of Simon Tooke’s proposed patches. The minimum Xcode version has been changed from 4 to 6 because recent source changes cause the 8u build to fail with Xcode 4. See

https://mail.openjdk.java.net/pipermail/jdk8u-dev/2021-May/013791.html

References to Xcode 4 have been removed from the root patch. Also, the regenerated generated-configure.sh isn’t in the root patch for the sake of clarity: I’ll add it to the final push.

In the hotspot patch:


  1.  The change to ostream.cpp is the fix proposed by Ziyi Luo for 8256720. I plan to close 8256720 as a dup of 8267545.
  2.  The change to os_bsd_x86.cpp was mistakenly left out of a previous backport (which I can’t find at the moment!)

Thanks,
Paul