Add document describing known issues in Ecma-335

[nguerrera]

@tmat

[nguerrera]

Also tagging @davkean and @CarolEidt

[CarolEidt]

It would be great to have a document where we could share issues more broadly - i.e. beyond those encountered in this context. Perhaps it belongs in the documentation directory of the coreclr repo (and yes, I realize that I'm probably the one that should create that ...)

[tmat]

I'd distinguish between ECMA-335 spec issues and implementation issues. Implementation issues in CLR should certainly be tracked by a document in coreclr repo. Since the goal of System.Reflection.Metadata package is provide public API for reading and writing ECMA-335 compliant files I think this repo is the right place for the spec errata.

Of course, we should push these changes into the ECMA-335 spec itself and once that's done we can delete this file.

[nguerrera]

Right now, I just wanted to save my notes. I'm not even sure what we should consider a spec bug and what we should consider implementation issues yet. I'd love to continue the conversation about the next steps towards where these notes should live, how they should be split, and the path towards amending the spec where appropriate, etc,, but I'd rather not block this PR on it.

[tmat]

👍

[davkean]

👍

[tmat]

@migueldeicaza @jbevain Nick wrote up issues we have recently found in ECMA-335 spec. So far these are signature encoding issues. We will be adding other issues here, as well as proposals for spec corrections. We'd like to hear your feedback. Specifically, how Mono.Cecil and Mono runtime handle these corner cases currently and how do you feel about the proposed changes (once we include them in the document).

[tmat]

//cc @vargaz

[nguerrera]

Added related issue links. Merging without waiting for tests since this is just a new .md file.