cxxmodules: support new round of Clang patches

These patches now support the `-MF` output, so remove the `none` support
added just for the old patchset which did not use it.

Also update the flag name to `-fmodule-output=`.

Due to the new Clang module mapper flag, use a new experimental support
UUID as well.

Source/cmCxxModuleMapper.cxx

@@ -47,7 +47,7 @@ std::string CxxModuleMapContentClang(CxxModuleLocations const& loc,
       // extension.
       mm << "-x c++-module\n";
 
-      mm << "-fsave-std-c++-module-file=" << *bmi_loc << '\n';
+      mm << "-fmodule-output=" << *bmi_loc << '\n';
       break;
     }
   }