[llvm] [EquivClasses] Fix signature of operator= (PR #130140)

[Ramkumar Ramachandra via llvm-commits]

artagnon wrote:

> > > I'd expect coverage for this in the unit tests?
> > 
> > 
> > The patch is a NFC.
> 
> NFC in the sense that it doesn't change the behavior of any LLVM programs, but we generally treat NFC a bit differently when it comes to ADTs or anything that's similarly/more unit testable. In which case we mostly test anything that can be observed on the API surface area. And this can be observed and tested.
> 
> Potentially modifying the existing unit test (assuming this function has existing unit test coverage, if not, it should be added) to initialize a non-const ref from the result of the assignment (& existing test coverage should be checking that resulting reference has the same address as the object)

Fixed, thanks.

https://github.com/llvm/llvm-project/pull/130140