chore: Toggle underconstrained check

[vezenovm]

Description

Problem*

Resolves

No issue as discovered when experimenting with https://github.com/iAmMichaelConnor/blob-lib/tree/domain-size-4096.

When compiling the circuit on the branch linked above using Noir master this was the result of timing nargo compile:

nargo compile --force --benchmark-codegen --silence-warnings  383.30s user 148.34s system 131% cpu 6:44.03 total

with under constrained check taking 200ms (about half the compilation time).

The check returned no bugs. If the developer wants to iterate more quickly and knows they are not changing unconstrained code or simply wishes to check for under constrained bugs later they should have the ability.

Summary*

This PR simply adds a flag --skip-underconstrained-check that skips calling ssa.check_for_underconstrained_values().

The blob-lib linked above compiled in half the time with the underconstrained check off:

nargo compile --force --skip-underconstrained-check --benchmark-codegen  192.15s user 295.27s system 220% cpu 3:41.33 total

Additional Context

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.