improve asm copy propagation for MOVE instruction

[xunilrj]

Description

This PR improve value propagation optimization in two ways:

1 - First, when the optimizer knows that both source and destination registers of the MOVE instruct have the same value and version; it will remove the instruction as it is useless;
2 - Otherwise, we propagate the value saying that destination now have the same value and version of the source register for other optimizations.

Gains on real contracts

Contract A From 143.672 KB to 142.76 KB : 912 bytes or 0.6%
Contract B from 26.488 KB to 26.264 KB: 224 bytes or 0.8%
Contract C from 22.176 KB to 22.096 KB: 80 bytes or or 0.3%

Checklist

• I have linked to any relevant issues.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation where relevant (API docs, the reference, and the Sway book).
  • If my change requires substantial documentation changes, I have requested support from the DevRel team
• I have added tests that prove my fix is effective or that my feature works.
• I have added (or requested a maintainer to add) the necessary Breaking* or New Feature labels where relevant.
• I have done my best to ensure that my PR adheres to the Fuel Labs Code Review Standards.
• I have requested a review from the relevant team or maintainers.

[codspeed-hq]

CodSpeed Performance Report

Merging #6641 will not alter performance

_{Comparing xunilrj/cpy-propagation-move (9566700) with master (64d1c6e)}

Summary

✅ 22 untouched benchmarks

[vaivaswatha]

Do you think we can have numbers before and after this change? maybe for just one or two important contracts if not our testsuite.