@defgroup LLVMCLinkTimeOptimizer Link Time Optimization @ingroup LLVMC
This provides a C-visible enumerator to manage status codes. This should map exactly onto the C++ enumerator LTOStatus.
This provides C interface to initialize link time optimizer. This allows linker to use dlopen() interface to dynamically load LinkTimeOptimizer. extern "C" helps, because dlopen() interface uses name to find the symbol.