When LLVMDEV is set and for an optimized ROOT build, build llvm as optimized with debug symbols. Before, llvm's build was as debug build if LLVMDEV is set, no matter what the ROOT build was.


git-svn-id: https://root.cern.ch/svn/root/trunk@49121 27541ba8-7e3a-0410-8455-c3a389f83636