fix Issue 12447 - variadic template functions hijack all eponymous enum and alias template overloads
fix Issue 11916 - [IFTI] Disabled by constraint overload with `out` with IFTI breaks overload resolution
fix Issue 11915 - Inconsistent overload resolution behaviour between `ref` and `out`
Merge pull request #4091 from 9rnsr/fix12447

Issue 12447 & 11915 & 11916 - fix overload resolution issue around IFTI and out parameter