feat: infer LLL IR function return values without metadata #400

All 70 tests pass in 0s

2 files + 1 10 suites +5 0s ⏱️ ±0s
70 tests ± 0 70 ✅ + 4 0 💤 ±0 0 ❌ - 4
140 runs +70 140 ✅ +74 0 💤 ±0 0 ❌ - 4

Results for commit 2f674f6. ± Comparison against earlier commit d7053e2.