make CMake script able to change llvm bitcode file name extension
make CMake script able to change llvm bitcode file name extension

The default LLVM bitcode suffix is .llvm

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