Define a "Brillig stdlib" for common functions for which the ACVM handles foreign calls.

[TomAFrench]

Problem

Noir is currently replacing the usage of a number of directives with Brillig functions which involve external calls. This is good as it will allow us to remove the Directive opcode in future however we're now performing foreign calls for several standard ACVM operations, e.g. checking equality between two values.

Happy Case

We should define a set of standard brillig functions such as inversion, division, etc. here in ACVM and have the ACVM catch the relevant foreign calls internally rather than requiring the environment to implement this logic.

Alternatives Considered

No response

Additional Context

ACVM JS currently won't process most Noir programs for this reason unless the caller includes the "invert" foreign call handler.

Would you like to submit a PR for this Issue?

Yes

Support Needs

No response

[TomAFrench]

This is just straight up incorrect. I think I brainfarted myself into thinking "brillig = foreign call" as we were using a foreign call to do inversion in the acvm_js tests but this isn't necessary.