LOG4J2-2750: Extended throwable class loading can be disabled

[carterkozak]

Implemented a new log4j2.enable.extended.throwable.class.loading flag which may be set to false in order to safely avoid performance pitfalls of class loading.

[carterkozak]

TODOS:

• Test coverage
• Documentation for the new flag
• Changelog

[rgoers]

@carterkozak I added support for requiresLocation() to LoggerConfig and various the various components a few releases ago. However, requiresLocation() should really be used as advice. If it is set to false it is still possible there is a custom component that didn't register its need for location information. With that in mind is there a way to leverage that somehow?

[jacky1193610322]

is this ok？