Extract out the common logical blocks from TClingCallFunc::Init into own routines.


git-svn-id: https://root.cern.ch/svn/root/trunk@48544 27541ba8-7e3a-0410-8455-c3a389f83636
Enrich the implementaion of Interpreter::mangleName, make it public and rename it
to maybeMangleDeclName (which is more talkative).
Use Interpreter::maybeMangleDeclName instead of duplicating code.


git-svn-id: https://root.cern.ch/svn/root/trunk@48545 27541ba8-7e3a-0410-8455-c3a389f83636