[8u] RFR: 8250876: Fix issues with cross-compile on macos

[Hohensee, Paul]

Please review this backport. It’s part of enabling Xcode 12 builds and has been backported to 11.

Original JBS: https://bugs.openjdk.java.net/browse/JDK-8250876
Original patch: https://hg.openjdk.java.net/jdk/jdk/rev/64490f533d62
11u patch: https://hg.openjdk.java.net/jdk-updates/jdk11u/rev/fbd5d019357b

8u root webrev: https://cr.openjdk.java.net/~phh/8250876/webrev.8u.root.00/
8u hotspot webrev: https://cr.openjdk.java.net/~phh/8250876/webrev.8u.hotspot.00/


The issue title doesn’t accurately describe the problem. What the patch fixes is that the latest versions of Xcode 12 no longer automatically check the Xcode SDK libraries under /System/Library/Frameworks/JavaVM.framework, but only those under /System/Library/Frameworks. JavaVM.framework has been replaced by JavaNativeFoundation, so in order to be backward compatible with earlier versions of Xcode 12 (and earlier major versions of Xcode) we must explicitly check for JavaVM.framework . See https://developer.apple.com/forums/thread/666686.



Tested using Xcode 6 (which has only JavaVM.framework) and 12.4 (which has only JavaNativeFoundation). No effect on non-osx builds.



Thanks,

Paul