Factor our common functionality and replace CreateTypeSourceInfo with getTrivialTypeSourceInfo.


git-svn-id: https://root.cern.ch/svn/root/trunk@49347 27541ba8-7e3a-0410-8455-c3a389f83636
Reuse not reimplement util function.


git-svn-id: https://root.cern.ch/svn/root/trunk@49348 27541ba8-7e3a-0410-8455-c3a389f83636