opCmp with template type not working.

[Jonathan Levi]

This is not working as expected:
> bool opCmp(string op, U)(U rhs) {

As it does work with:
> auto opBinary(string op, U)(U rhs) {


With:

> struct X {
>     int x;
>     auto opBinary(string op, U)(U rhs) {
>             return mixin("x "~op~" rhs");
>         }
>     bool opCmp(string op, U)(U rhs) {
>         return mixin("x "~op~" rhs");
>     }
> }

This compiles:
> X(5) + 4
This does not:
> X(5) < 4

Full example code: https://run.dlang.io/is/Beflkt

Is this a Bug?