Description

Problem*

Resolves #6533

Summary*

Allows Instruction::Intrinsic types to be deduplicated in constant_folding if the Context is in use_constraint_info mode, and the Intrinsic is one that doesn't have a side effect other than the possibility of violating an implicit constraint on its inputs, which should be preserved in the first occurrence.

Additional Context

I found it a bit confusing why we're using use_constraint_info for these whenrequires_acir_gen_predicate returns false for all these instructions, which will cause cached_instruction_results to contain None for the predicate regardless of use_constraint_info. For some, but not all intrinsics, the predicate that tells whether the side effect is enabled is attached to their inputs during Ssa::flatten_cfg, and they don't depend any more on the enable_side_effect instruction. But it seems like this flag is the one that communicates whether we want such instructions to be deduplicated, so I used it even though I'm not sure what adverse effect we would see if we just returned true for these, other than the implicit coupling by knowing that flatten_cfg has done things in a certain way.

Another method that seems to have some of the truth is remove_enable_side_effects::Context::responds_to_side_effects_var

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.