[clang] [CIR] Record the source level identity of functions on cir.func (PR #207261)

[Erich Keane via cfe-commits]

https://github.com/erichkeane commented:

I'm on the fence as defined now.  I think this is absolutely the right direction (an attribute on a `cir.func` that tells us additional information for optimization purposes), but I think the data it is currently holding isn't particularly useful.

Also, the 'instance-method' not telling us what the parent object type is, is a touch awkward/perhaps limiting as well?

On the other hand, I very much expect this attribute to evolve over time, and perhaps this is a good starting point.  I AM a little uncomfortable with it as a starting point at the moment because I suspect that the opts you have next are not necessarily sound because of the information in it, but I am a little OK discussing that in the next patches?



https://github.com/llvm/llvm-project/pull/207261