RFR: Disable Shenandoah with --with-jvm-features=-shenandoahgc

[Roman Kennke]

Am 12.06.2018 um 12:24 schrieb Aleksey Shipilev:
> http://cr.openjdk.java.net/~shade/shenandoah/conditional-compilation/webrev.01/
> 
> Upstream merge brought us conditional GC compilation. This patch makes sure we are able to build
> with Shenandoah disabled. This should allow building Minimal without additional work, and lays the
> ground for disabling Shenandoah compilation for unsupported platforms.
> 
> Testing: tier1 with -shenandoahgc, tier3_gc_shenandoah with +shenandoahgc
> 
> Thanks,
> -Aleksey
> 


+  JVM_EXCLUDE_PATTERNS += gc/shenandoah shenandoahSupport
shenandoahBarrierSet

Doesn't gc/shenandoah also match shenandoahSupport and
shenandoahBarrierSet stuff, now that they all reside under gc/shenandoah
somewhere?

Other than that, looks good!
Thanks, Roman