RFR: 8200737: Move GC code out of Arguments::check_vm_args_consistency into GCArguments

[Stefan Karlsson]

Hi all,

Please review this patch to move GC code out of 
Arguments::check_vm_args_consistency into GCArguments.

http://cr.openjdk.java.net/~stefank/8200737/webrev.01/
https://bugs.openjdk.java.net/browse/JDK-8200737

This moves one of the usages of INCLUDE_ALL_GCS out of the runtime code 
into GC code, which helps the code in:
https://bugs.openjdk.java.net/browse/JDK-8200729

I've verified that the changed flags are not used between the previous 
location and the new location.

Thanks,
StefanK