Fix handling of: case(1)

Fix the use of postinc directly in function call with parameter than are references.
Correct the constness in the case: Object * const &front() const; (i.e Object*const vs Object const*).


git-svn-id: http://root.cern.ch/svn/root/trunk@21352 27541ba8-7e3a-0410-8455-c3a389f83636