Access checks in JIT interface methods

[nattress]

The final section of CEEInfo::getCallInfo (https://github.com/dotnet/coreclr/blob/5f93d3b1c48ba6916d5f31d79cb7c17d564eecef/src/vm/jitinterface.cpp#L5597) deals with access checks validating the declarative authority of a given caller to call the callee. This is currently missing in the CPAOT compiler. Similar checks needed in CEEInfo::getFieldInfo.

[MichalStrehovsky]

We should look into sharing the logic with ILVerify: https://github.com/dotnet/corert/blob/28cbd27c5a809c081d6edabb98ab216baf09bf98/src/ILVerification/src/AccessVerificationHelpers.cs

[davidwrighton]

This isn't needed for the 5.0 release.

[trylek]

I believe we need to either address this for the .NET 6 shipping release or at least convince ourselves that we don't need to. I think we do because silently violating access rights while emitting the R2R native image violates the principle of R2R vs. JIT equivalence. @jkotas, could you please correct me if I'm wrong?

[jkotas]

Violating visibility rules is invalid IL. In general, invalid IL can lead to observable behavior difference between AOT and JIT, or between optimization levels. These differences are by design.

I think that this is nice-to-fix. We should look at it together with all other types of invalid IL detection we can be doing. I think it would be fine to implement these additional checks reactively, only once somebody reports them as a problem.

[mangod9]

moving to 7 based on the discussion above.

[davidwrighton]

We don't need these.