Enhance cir.atomic.cmp_xchg and cir.atomic.xchg verifiers

[bcardosolopes]

This is comparing contents of the object pointed to by a !cir.ptr<!ty_S> pointer to a !u64i value

Originally posted by @bcardosolopes in #1373 (comment)

[Icaro-Nunes]

Hello, I'm new here and would like to contribute! Can you provide more information on this issue? I have read the mentioned PR and previous issue but could not understand completely what enhancements should be made.

[bcardosolopes]

Hi @Icaro-Nunes, the pointee should match the value to compare, should be implemented in the ::verify method for both operations

[Icaro-Nunes]

Ok, I'm looking at it!

[Icaro-Nunes]

Hello @bcardosolopes , I just opened a draft PR for this issue! I think the only thing I was not able to figure out is how to write a test that forces the type checking in ::verify to fail, since most attempts get caught at function argument checking (there is an example in the PR).

[bcardosolopes]

I didn't see it, thanks for reaching out. Added a comments over there!