-insert-edge-profiling inserts call to the llvm_start_edge_profiling
function which is a part of a profiling runtime library. This library
must be linked into your executable.
The runtime library isn't built automatically. To build it, please, run
make in the $LLVMOBJDIR/runtime directory. If it complains about
LLVMGCCDIR not set, it means you have to reconfigure LLVM with