cmake LibElf examples

SimonKagstrom/kcov cmake/FindElfUtils.cmake :12 

find_package (LibElf)

ROCm/ROCR-Runtime runtime/hsa-runtime/CMakeLists.txt :86 

find_package(LibElf REQUIRED)

RIKEN-SysSoft/mckernel executer/user/lib/libdwarf/CMakeLists.txt :8 

find_package(LibElf REQUIRED)