This brings these enums to match the rest of the code and fixes 2 warnings under clang about using C++11 extensions.
Clang 4.0 introduced -Wdouble-promotion, so check for and disable that on clang as we do on gcc. The old style casts warning is already disabled globally in this file for clang, so it doesn't need to be re-disabled within this scope.
Bruce Mitchener