Merge

8179954: AArch64: C1 and C2 volatile accesses are not sequentially consistent Reviewed-by: roland

8180325: Use ClassLoaderData::classes_do for CDS classes Summary: Use closures and ClassLoaderData::classes_do instead of SystemDictionary::classes_do Reviewed-by: iklam, jiangli

8178604: JVM does not allow defining boot loader modules in exploded build after module system initialization Summary: Allow defining of boot loader modules after initialization but add locks to synchronize access to exploded build list Reviewed-by: dholmes, lfoltan