fix(ssa refactor): Fix failed_to_inline_a_function being set for intrinsics

[jfecher]

Description

Problem*

The change to add handling for brillig functions changed failed_to_inline_a_function to be true whenever a function failed to inline. We want this not to be set if the function we found is an intrinsic since those do not need to be inlined and added a comment since this is otherwise a subtle difference.

Fixes #1659

Summary*

This PR sets out to

Example

Before:

After:

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.

[jfecher]

Just confirmed this PR results in exactly 1 function in the final IR for every example mentioned in #1659, however it is worth noting that all of these examples are still failing for other reasons.

[joss-aztec]

LGTM