[llvm] [LangRef] Add a description of the semantics of call signatures. (PR #136189)

[Mehdi Amini via llvm-commits]

joker-eph wrote:

> This updates LangRef to reflect current LLVM semantics. I understand that you think these semantics are not desirable, but LangRef should still reflect the current semantics.

This is a weird reasoning: you introduce a bug / regression and then claim this is the current semantics... How is that OK?

>  the current design is intentional, so calling this a "bug" is disingenuous. It is not the case that someone just forgot to implement a verifier check -- the lack of a verifier check is deliberate.

How so? Was this discussed and considered like a desirable change in LLVM verification? You didn't provide such pointers in the bug discussion I believe.

> If we wanted to make any change away from the current semantics, it would have to go through an RFC 

CF above: where was this particular behavior change discussed in an RFC in the first place?

https://github.com/llvm/llvm-project/pull/136189