[TableGen] Track location for Inits

[jurahul]

TableGen's Init and subclasses do not track locations. This issue is to enhance the Init to also track its location. Currently, the Init nodes are uniqued using a FoldingSet, so we can either do away with that or add an indirection so that an Init node is its location + a pointer to the uniqued "contents".

Once locations are tracked for Inits, we also need to enhance the error reporting to use these locations.

[pchaudhuri-nv]

Hello All,

I would like to start working on this issue. And have got some guidance from Rahul regarding the same.
Can this issue be assigned to me, incase no-one is working on this ?

Thank you,
Prerona

[pchaudhuri-nv]

I just want to update that after guidance of Rahul Joshi, we have decided to create a wrapper class that will point to the unique payload. I have started work on that (progress slower than I expect, both due to me not being familiar with code + other commitments) - right now I run into issue while building AArch64 backend, so I am currently debugging that.

Will update on progress again soon.

Thank you