RFR: JDK-8239799 Cross-compilation ARM32/AARCH clientvm builds fails after JDK-8239450

Thu Feb 27 14:56:47 UTC 2020

The JVM feature rewrite changed spec.gmk so that JVM_FEATURE_<variant> 
was only set for the variants actually being built. However, in 
buildjdk-spec.gmk we override the selected variant with 'server' when 
building the buildjdk, but we relied on the set of features detected for 
the target jdk. This worked most of the time (?) in practice, but was 
arguably not correct. And with the rewrite this failed miserably, since 
the JVM was built without any features whatsoever, including any kind of 
GC, which caused the buildjdk to fail running with the message:

[buildjdk] Creating interim java.logging.jmod
Error occurred during initialization of VM
Option -XX:+UseSerialGC not supported

I've now handpicked a careful selection of features to turn on, to 
hopefully get maximum performance during the build, without adding 
features (such as monitoring etc) that is not needed.

Bug: https://bugs.openjdk.java.net/browse/JDK-8239799
WebRev: 
http://cr.openjdk.java.net/~ihse/JDK-8239799-cross-compiling-client-fails-after-jvm-feature-rewrite/webrev.01

/Magnus