lib.data.{Field, Layout, Const}: add __hash__

[rroohhh]

No description provided.

[codecov]

Codecov Report

❌ Patch coverage is 87.50000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 91.23%. Comparing base (5689b6b) to head (bb15bf3).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
amaranth/lib/data.py	87.50%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1623      +/-   ##
==========================================
- Coverage   91.24%   91.23%   -0.01%     
==========================================
  Files          44       44              
  Lines       11394    11402       +8     
  Branches     2223     2224       +1     
==========================================
+ Hits        10396    10403       +7     
  Misses        836      836              
- Partials      162      163       +1     

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[whitequark]

You should also add tests that these types are hashable.

[whitequark]

Could you update the changelog?

[whitequark]

Thanks!

[whitequark]

Sorry, didn't notice it was waiting on me still.