test(vm): add comprehensive unit tests for bytecode argument encoding and decoding (#4240)

[ParthMozarkar]

Summary

This PR adds comprehensive unit tests for bytecode argument encoding and decoding in:

core/engine/src/vm/opcode/args.rs

as requested in issue #4240.

What’s Included

• ✅ Tests verifying correct encoding and decoding of opcode arguments.
• ✅ Round-trip validation (encode → decode → assert equality).
• ✅ Boundary condition tests for edge-case values.
• ✅ Out-of-bounds read tests to ensure panics occur as expected.
• ✅ Negative test cases validating safety guarantees.

Motivation

Bytecode argument handling is a critical component of the VM execution pipeline.
These tests strengthen confidence in argument parsing correctness and protect against silent corruption or unsafe memory access.

By covering both valid and invalid cases, this improves robustness and makes future refactors safer.

Verification

• cargo test passes successfully.
• No Clippy warnings introduced.
• Formatting verified with cargo fmt.

Closes #4240

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	52,862	52,862	0
Passed	49,505	49,504	-1
Ignored	2,261	2,262	+1
Failed	1,096	1,096	0
Panics	0	0	0
Conformance	93.65%	93.65%	-0.00%

[Sharktheone]

I think you should base this off main and not off your own branch with console.table implemented

[ParthMozarkar]

Thanks for pointing that out you're right.

I’ve rebased the branch on top of main and force pushed the updated changes so the PR now only contains the unit test additions for #4240.

Please let me know if anything else needs adjustment. 🙌

[ParthMozarkar]

@jedel1043
everything is perfect i feel like so if you could please review it for merging...it would be great !!