chore: rework workspace structure for utils crates (#4886)

# Description

## Problem\*

Resolves <!-- Link to GitHub Issue -->

## Summary\*

This PR flattens a layer of nesting from our crate structure. I've
renamed `arena` to `noirc_arena` so we can publish to crates.io in the
future.

## Additional Context



## Documentation\*

Check one:
- [x] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[For Experimental Features]** Documentation to be submitted in a
separate PR.

# PR Checklist\*

- [x] I have tested the changes locally.
- [x] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.

Cargo.toml

@@ -4,17 +4,15 @@ members = [
     # Aztec Macro crate for metaprogramming
     "aztec_macros",
     # Compiler crates
+    "compiler/noirc_arena",
     "compiler/noirc_evaluator",
     "compiler/noirc_frontend",
     "compiler/noirc_errors",
     "compiler/noirc_driver",
     "compiler/noirc_printable_type",
     "compiler/fm",
     "compiler/wasm",
-    # Utility crates used by the Noir compiler
-    "compiler/utils/arena",
-    "compiler/utils/iter-extended",
-    # Crates related to tooling built ontop of the Noir compiler
+    # Crates related to tooling built on top of the Noir compiler
     "tooling/backend_interface",
     "tooling/bb_abstraction_leaks",
     "tooling/lsp",
@@ -35,6 +33,8 @@ members = [
     "acvm-repo/brillig_vm",
     "acvm-repo/blackbox_solver",
     "acvm-repo/bn254_blackbox_solver",
+    # Utility crates
+    "utils/iter-extended",
 ]
 default-members = ["tooling/nargo_cli", "tooling/acvm_cli"]
 resolver = "2"
@@ -61,9 +61,8 @@ acvm_blackbox_solver = { version = "0.44.0", path = "acvm-repo/blackbox_solver",
 bn254_blackbox_solver = { version = "0.44.0", path = "acvm-repo/bn254_blackbox_solver", default-features = false }
 
 # Noir compiler workspace dependencies
-arena = { path = "compiler/utils/arena" }
 fm = { path = "compiler/fm" }
-iter-extended = { path = "compiler/utils/iter-extended" }
+noirc_arena = { path = "compiler/noirc_arena" }
 noirc_driver = { path = "compiler/noirc_driver" }
 noirc_errors = { path = "compiler/noirc_errors" }
 noirc_evaluator = { path = "compiler/noirc_evaluator" }
@@ -80,6 +79,9 @@ noirc_abi = { path = "tooling/noirc_abi" }
 bb_abstraction_leaks = { path = "tooling/bb_abstraction_leaks" }
 acvm_cli = { path = "tooling/acvm_cli" }
 
+# Misc utils crates
+iter-extended = { path = "utils/iter-extended" }
+
 # LSP
 async-lsp = { version = "0.1.0", default-features = false }
 lsp-types = "0.94.1"

compiler/utils/arena/Cargo.toml → compiler/noirc_arena/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "arena"
+name = "noirc_arena"
 version.workspace = true
 authors.workspace = true
 edition.workspace = true

compiler/noirc_frontend/Cargo.toml

@@ -10,10 +10,10 @@ license.workspace = true
 
 [dependencies]
 acvm.workspace = true
+noirc_arena.workspace = true
 noirc_errors.workspace = true
 noirc_printable_type.workspace = true
 fm.workspace = true
-arena.workspace = true
 iter-extended.workspace = true
 chumsky.workspace = true
 thiserror.workspace = true

compiler/noirc_frontend/src/hir/def_map/mod.rs

@@ -5,8 +5,8 @@ use crate::macros_api::MacroProcessor;
 use crate::node_interner::{FuncId, GlobalId, NodeInterner, StructId};
 use crate::parser::{parse_program, ParsedModule, ParserError};
 use crate::token::{FunctionAttribute, SecondaryAttribute, TestScope};
-use arena::{Arena, Index};
 use fm::{FileId, FileManager};
+use noirc_arena::{Arena, Index};
 use noirc_errors::Location;
 use std::collections::{BTreeMap, HashMap};
 mod module_def;

compiler/noirc_frontend/src/hir/type_check/mod.rs

@@ -672,7 +672,7 @@ pub mod test {
         }
 
         fn local_module_id(&self) -> LocalModuleId {
-            LocalModuleId(arena::Index::unsafe_zeroed())
+            LocalModuleId(noirc_arena::Index::unsafe_zeroed())
         }
 
         fn module_id(&self) -> ModuleId {
@@ -724,7 +724,7 @@ pub mod test {
         let mut def_maps = BTreeMap::new();
         let file = FileId::default();
 
-        let mut modules = arena::Arena::default();
+        let mut modules = noirc_arena::Arena::default();
         let location = Location::new(Default::default(), file);
         modules.insert(ModuleData::new(None, location, false));
 

compiler/noirc_frontend/src/node_interner.rs

@@ -2,9 +2,9 @@ use std::borrow::Cow;
 use std::collections::HashMap;
 use std::ops::Deref;
 
-use arena::{Arena, Index};
 use fm::FileId;
 use iter_extended::vecmap;
+use noirc_arena::{Arena, Index};
 use noirc_errors::{Location, Span, Spanned};
 use petgraph::algo::tarjan_scc;
 use petgraph::prelude::DiGraph;

compiler/noirc_frontend/src/resolve_locations.rs

@@ -1,4 +1,4 @@
-use arena::Index;
+use noirc_arena::Index;
 use noirc_errors::Location;
 
 use crate::hir_def::expr::HirExpression;

compiler/noirc_frontend/src/tests.rs

@@ -31,8 +31,8 @@ mod test {
         hir::def_map::{CrateDefMap, LocalModuleId},
         parse_program,
     };
-    use arena::Arena;
     use fm::FileManager;
+    use noirc_arena::Arena;
 
     pub(crate) fn has_parser_error(errors: &[(CompilationError, FileId)]) -> bool {
         errors.iter().any(|(e, _f)| matches!(e, CompilationError::ParseError(_)))