convert linker choice to (advanced) choice. only for Clang and GNU at the moment

  set(MEMORYCHECK_COMMAND "${VALGRIND_BINARY}" CACHE FILEPATH "Memory Check Command")

  set(MEMORYCHECK_COMMAND_OPTIONS "${VALGRIND_DEFAULT_OPTIONS}" CACHE STRING "Memory Check Command Options")

  # check if a faster linker is available

  # check if a faster linker is available.

  # only verified with GNU and Clang compilers and new CMake

  if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.13)

    if((${CMAKE_CXX_COMPILER_ID} STREQUAL "GNU")

        OR (${CMAKE_CXX_COMPILER_ID} STREQUAL "Clang"))

      include(CheckCXXCompilerFlag)

      set(CMAKE_CUSTOM_LINKER_DEFAULT default)

      check_cxx_compiler_flag(-fuse-ld=lld HAVE_LLD_LINKER)

      check_cxx_compiler_flag(-fuse-ld=gold HAVE_GOLD_LINKER)

      check_cxx_compiler_flag(-fuse-ld=bfd HAVE_BFD_LINKER)

      if(HAVE_LLD_LINKER)

      target_link_options(lammps PUBLIC -fuse-ld=lld)

        set(CMAKE_CUSTOM_LINKER_DEFAULT lld)

      elseif(HAVE_GOLD_LINKER)

      target_link_options(lammps PUBLIC -fuse-ld=gold)

        set(CMAKE_CUSTOM_LINKER_DEFAULT gold)

      elseif(HAVE_BFD_LINKER)

        set(CMAKE_CUSTOM_LINKER_DEFAULT bfd)

      endif()

      set(CMAKE_CUSTOM_LINKER_VALUES lld gold bfd default)

      set(CMAKE_CUSTOM_LINKER ${CMAKE_CUSTOM_LINKER_DEFAULT} CACHE STRING "Choose a custom linker for faster linking (lld, gold, bfd, default)")

      validate_option(CMAKE_CUSTOM_LINKER CMAKE_CUSTOM_LINKER_VALUES)

      mark_as_advanced(CMAKE_CUSTOM_LINKER)

      if(NOT "${CMAKE_CUSTOM_LINKER}" STREQUAL "default")

        target_link_options(lammps PUBLIC -fuse-ld=${CMAKE_CUSTOM_LINKER})

      endif()

    endif()

  endif()