dialects: [arith] Add extended multiplication operations

[math-fehr]

Add the mului_extended and mulsi_extended from the arith dialect in MLIR

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.64%. Comparing base (16954e0) to head (3dbe379).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2670      +/-   ##
==========================================
- Coverage   89.64%   89.64%   -0.01%     
==========================================
  Files         361      362       +1     
  Lines       46254    46373     +119     
  Branches     6992     7012      +20     
==========================================
+ Hits        41464    41569     +105     
- Misses       3719     3726       +7     
- Partials     1071     1078       +7     

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