perf: remove usage of reg_pc and reg_insns_ptr

[GunaDD]

Closes INT-5484

[GunaDD]

Reth benchmark after this PR:

E1: 254 ms
E2: 405ms

[github-actions]

group	app.proof_time_ms	app.cycles	app.cells_used	leaf.proof_time_ms	leaf.cycles	leaf.cells_used
verify_fibair	252	322,610	2,058,654	-	-	-
fibonacci	964	1,500,209	2,100,402	-	-	-
regex	2,376	4,137,502	17,695,216	-	-	-
ecrecover	701	122,859	2,265,100	-	-	-
pairing	1,460	1,745,742	25,468,210	-	-	-

Commit: a2bf15b

Benchmark Workflow

[codspeed-hq]

CodSpeed Performance Report

Merging #2250 will degrade performances by 18.73%

_{Comparing feat/register-freeup (a2bf15b) with feat/aot (b0a067d)}

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

Summary

⚡ 2 improvements
❌ 1 regression
✅ 21 untouched
⏩ 36 skipped¹

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Mode	Benchmark	BASE	HEAD	Change
⚡	WallTime	benchmark_execute[fibonacci_iterative]	3.9 ms	2.5 ms	+52.6%
❌	WallTime	benchmark_execute[revm_snailtracer]	6.9 ms	8.5 ms	-18.73%
⚡	WallTime	benchmark_execute_metered[quicksort]	10.9 ms	9.1 ms	+19.69%

Footnotes

1. 36 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩