Use enums defined in cmOutputConverter using their fully qualified name.

Mostly automated:

values=("RelativeRoot" "NONE" "FULL" "HOME" "START" "HOME_OUTPUT" "START_OUTPUT"
        "OutputFormat" "UNCHANGED" "MAKERULE" "SHELL" "WATCOMQUOTE" "RESPONSE"
        "FortranFormat" "FortranFormatNone" "FortranFormatFixed" "FortranFormatFree")
for i in "${values[@]}"; do git grep -l cmLocalGenerator::$i | xargs sed -i "s|cmLocalGenerator::$i|cmOutputConverter::$i|g"; done