core: Add support for nested inferrence in IRDL

[math-fehr]

This PR allows us to infer the types of some operands and results from the types of other operands and results.

It does so by adding three functions in AttrConstraint:

• get_resolved_variables: This function returns the set of ConstraintVar that will be set during verification.
• can_infer: Returns True if we can infer a unique attribute represented by the AttrConstraint from the assignment of ConstraintVar.
• infer: Returns the only attribute that satisfy this constraint, given the constraint variables.

We use these methods to get all ConstraintVar from the parsed operand/result types present in the syntax, then infer the constraints on the types that are not in the syntax.

[codecov]

Codecov Report

Attention: 7 lines in your changes are missing coverage. Please review.

Comparison is base (37968f8) 90.03% compared to head (0e867f0) 90.04%.
Report is 1 commits behind head on main.

Files	Patch %	Lines
xdsl/irdl/irdl.py	79.41%	3 Missing and 4 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2005      +/-   ##
==========================================
+ Coverage   90.03%   90.04%   +0.01%     
==========================================
  Files         289      289              
  Lines       35768    35882     +114     
  Branches     5275     5287      +12     
==========================================
+ Hits        32202    32309     +107     
- Misses       2814     2818       +4     
- Partials      752      755       +3     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[PapyChacal]

Yaaay 🚀