feat: skip remove_enable_side_effects pass on brillig functions (#6199

)

# Description

## Problem\*

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

## Summary\*

PR described in comment in code.

## 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.

compiler/noirc_evaluator/src/ssa/opt/remove_enable_side_effects.rs

@@ -16,7 +16,7 @@ use crate::ssa::{
     ir::{
         basic_block::BasicBlockId,
         dfg::DataFlowGraph,
-        function::Function,
+        function::{Function, RuntimeType},
         instruction::{BinaryOp, Instruction, Intrinsic},
         types::Type,
         value::Value,
@@ -37,6 +37,11 @@ impl Ssa {
 
 impl Function {
     pub(crate) fn remove_enable_side_effects(&mut self) {
+        if matches!(self.runtime(), RuntimeType::Brillig) {
+            // Brillig functions do not make use of the `EnableSideEffects` instruction so are unaffected by this pass.
+            return;
+        }
+
         let mut context = Context::default();
         context.block_queue.push(self.entry_block());