Added in version 3.29.
This controls how the value of the CMAKE_<LANG>_USING_LINKER_<TYPE>
variable should be interpreted. The supported linker mode values are:
FLAGCMAKE_<LANG>_USING_LINKER_<TYPE> holds a
semicolon-separated list of flags to be passed
to the compiler frontend. This is also the default behavior if
CMAKE_<LANG>_USING_LINKER_MODE is not set.
TOOLCMAKE_<LANG>_USING_LINKER_<TYPE> holds the path to the linker
tool.