add -fno-rtti in makefile
add -fno-rtti in makefile

LLVM library is built with -fno-rtti flag by default. I think
most users do not have the LLVM library built with rtti.

rgly/LLVM-Tracer,amritamaz/LLVM-Tracer,amritamaz/LLVM-Tracer,rgly/LLVM-Tracer,amritamaz/LLVM-Tracer,rgly/LLVM-Tracer