[clang] [CIR] Add CxxCTorAttr, CxxDTorAttr, CxxAssignAttr, CxxSpecialMemberAttr to cir::FuncOp (PR #167975)

[Hendrik Hübner via cfe-commits]

HendrikHuebner wrote:

> > > In general it would be nice to have more helper methods on operation and attributes like `isCtor`, `isMoveCtor` etc.
> > 
> > 
> > Should I add this to the `extraClassDefinitions` of `FuncOp` in CIROps.td?
> 
> Yes, that would be probably best.

Already done :)

(Although slightly differently)

https://github.com/llvm/llvm-project/pull/167975