Epic: More modular frontend

[michaeljklein]

Problem

The frontend could be split into more modular parts by reducing repetition, grouping some Type variants by their behavior, and splitting out some code into separate crates

Happy Case

Reduce repetition

• Use NodeInterner and Type impl helper functions (these functions are sometimes inlined)
• Use the same field names in the AST and HIR, e.g. bounds in NoirTrait vs. trait_bounds in Trait
• Use helper functions for hir_def fields and make them private, e.g. set_methods for Trait, or else consider removing those helper functions

Grouping types by behavior

Each of the types in these groups shares methods, e.g. the sized container types all evaluate their lengths to u32's, struct and tuple types both require iteration over their fields, etc.

• Sized container types:
  • [T; N]
  • str<N>
  • fmtstr<N, T>
• Struct + Tuple
• Integral types:
  • Field
  • bool
  • ()?
• Arithmetic generics:
  • InfixExpr
  • CheckedCast
  • Constant
• Type variables:
  • TypeVariable
  • NamedGeneric

Separate crates

• Make a crate for all integral binary operations, including evaluation, printing, etc. (used in resolution, arithmetic generics, comptime interpreter, noirc_evaluator, and possibly other locations)
• Split off definition of AST into a separate crate #4852

Workaround

None

Workaround Description

No response

Additional Context

No response

Project Impact

Nice-to-have

Blocker Context

No response

Would you like to submit a PR for this Issue?

None

Support Needs

No response

[michaeljklein]

@TomAFrench