RFR: 8154110: Update class* and safepoint* logging subsystems

[Max Ockner]

Hello,

This change factors the tags from the class and safepoint logging 
subsystems into smaller tags, including "class" and "safepoint" tags 
which are included in tag combination in their respective subsystems.

classresolve -> class+resolve
classload -> class+load
classunload -> class+unload
classpath -> class+path
classloaderdata -> class+loaderdata
classload+constraints -> class+loaderconstraints
classinit -> class+init
classload+preorder -> class+preorder

safepointcleanup -> safepoint+cleanup

class+loaderdata can be further factored into class+load+data. Same with 
class+loaderconstraints.

Bug: https://bugs.openjdk.java.net/browse/JDK-8154110
webrev(hotspot): http://cr.openjdk.java.net/~mockner/8154110.hotspot/
webrev(jdk): http://cr.openjdk.java.net/~mockner/8154110.jdk/

Tested with jtreg hotspot tests. jdk tests currently running.

Thanks,
Max