Normalize compute and constrain dependencies

[iangneal]

Summary

Normalizes compute/constrain dependencies to logical program signals on top of #651. This is PR 5 of 6 in the stacked series.

Related issues

No standalone issue; depends on #651.

Changes

• Track direct equality aliases separately and prefer logical inputs/component paths over POD and temporary roots.
• Normalize nondeterministic allocations to written signals.
• Remove only proven neutral loop-zero initializers while preserving meaningful zero dependencies.
• Retain distinct logical component paths when alias candidates overlap an output.
• Add regressions for deferred components, input PODs, child-output rebasing, nondeterministic arrays, and loop accumulation.
• Add changelogs/unreleased/iangneal__dependency-normalization.yaml.

Testing

• git diff --check
• Focused compute/constrain normalization regressions
• nix build -L on this exact stacked commit (371 lit tests and 1,312 unit/CAPI tests passed)

Submission checklist

• If I am an external contributor, this PR has a linked issue marked approved; otherwise, this does not apply.
• I added or updated tests for all relevant behavior, or explained above why tests are not needed.
• I updated the relevant TableGen or other documentation, or explained above why documentation is not needed.
• I added a changelog entry describing user-visible changes. (create-changelog in the Nix development shell creates a template.)
• I enabled Allow edits from maintainers if this PR comes from a fork.

AI assistance

• No AI tools contributed to this PR.
• AI tools contributed to this PR.

Tools used: OpenAI Codex.

How the tools contributed: Codex helped partition the original working-tree change, preserve dependency ordering, add focused regressions and changelog entries, and prepare this draft PR.

How I verified the contribution: Reviewed the isolated diff and ran git diff --check, the focused analysis regressions through the project test suite, and nix build -L on this exact commit.

[github-actions]

Test Results

0 tests  ±0   0 ✅ ±0   0s ⏱️ ±0s
0 suites ±0   0 💤 ±0 
0 files   ±0   0 ❌ ±0 

Results for commit 0fc6df7. ± Comparison against base commit 3322a6a.

♻️ This comment has been updated with latest results.