fix: display correct range for u128 in OverflowingAssignment error

[TomAFrench]

Description

Problem*

Resolves #2623

Summary*

This PR addresses an overflow which was occurring when calculating the maximum value of a u128. We now special case u128 and only calculate the maximum for smaller types.

Documentation

• This PR requires documentation updates when merged.

  • I will submit a noir-lang/docs PR.
  • I will request for and support Dev Rel's help in documenting this PR.

Additional Context

PR Checklist*

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

[vezenovm]

I don't think this is the right error to display for u128. Our max supported integer size is u127. We have an UnsupportedIntegerSize runtime error that we handle when converting SSA bianry ops to ACIR. We should do the same thing for assignments and binary ops in SSA as well. Until we have improved general overflow checks in SSA this special case should just check the annotated type against the bit count and return an UnsupportedIntegerSize in the type check.

[kevaundray]

What is that status of this fix?