feat: loop keyword in runtime and comptime code

[asterite]

Description

Problem

No tracking issue, but implements loop in unconstrained and comptime code

Summary

Additional Context

Note that right now this doesn't work if there's no break inside a loop:

• Function::returns() in SSA expect a return to be there
• Inlining breaks because it can't find a return terminator

I also had to change some unrolling code that assumed there's an induction variable or a single instruction in a loop header, because now that's not true.

I'm not sure how to handle the inlining code... should we abandon the assumption that functions always have a return terminator? If so, how does the inlining code logic needs to change to handle that?

Documentation

Check one:

• No documentation needed.
• Documentation included in this PR.
• [For Experimental Features] Documentation to be submitted in a separate PR.

PR Checklist

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[github-actions]

Compilation Report

Program	Compilation Time	%
sha256_regression	0.982s	-10%
regression_4709	0.776s	-8%
ram_blowup_regression	16.100s	-4%
rollup-root	3.720s	6%
rollup-merge	2.128s	0%
rollup-block-root-single-tx	138.000s	0%
rollup-block-root-empty	2.038s	-2%
rollup-block-root	153.000s	9%
rollup-block-merge	3.668s	3%
rollup-base-public	27.960s	-1%
rollup-base-private	10.080s	-6%
private-kernel-tail	1.003s	-3%
private-kernel-reset	6.684s	4%
private-kernel-inner	2.086s	6%

[github-actions]

Execution Report

Program	Execution Time	%
sha256_regression	0.051s	-4%
regression_4709	0.001s	0%
ram_blowup_regression	0.607s	-2%
rollup-root	0.104s	0%
rollup-merge	0.006s	0%
rollup-block-root	36.600s	0%
rollup-block-merge	0.104s	0%
rollup-base-public	1.222s	2%
rollup-base-private	0.451s	-1%
private-kernel-tail	0.019s	0%
private-kernel-reset	0.312s	-1%
private-kernel-inner	0.067s	0%

[github-actions]

Execution Memory Report

Program	Peak Memory
keccak256	74.71M
workspace	123.95M
regression_4709	316.02M
ram_blowup_regression	512.62M
rollup-root	498.31M
rollup-merge	473.05M
rollup-block-root	1.22G
rollup-block-merge	498.33M
rollup-base-public	734.18M
rollup-base-private	590.51M
private-kernel-tail	180.91M
private-kernel-reset	245.52M
private-kernel-inner	208.92M

[github-actions]

Compilation Memory Report

Program	Peak Memory
keccak256	77.65M
workspace	123.93M
regression_4709	424.15M
ram_blowup_regression	1.46G
rollup-root	601.26M
rollup-merge	494.24M
rollup-block-root-single-tx	16.06G
rollup-block-root-empty	488.41M
rollup-block-root	16.07G
rollup-block-merge	601.26M
rollup-base-public	2.38G
rollup-base-private	1.14G
private-kernel-tail	207.46M
private-kernel-reset	584.49M
private-kernel-inner	294.68M