fix: use element_size() instead of computing it with division (#5939)

# Description

## Problem

Resolves #5936

## Summary


## Additional Context

I was computing an array's element size in a way that could lead to
dividing by zero, but there was already a method to get the element
size.

## 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.

---------

Co-authored-by: jfecher <jake@aztecprotocol.com>

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

@@ -377,13 +377,12 @@ fn handle_array_get_group(
     next_out_of_bounds_index: &mut Option<usize>,
     possible_index_out_of_bounds_indexes: &mut Vec<usize>,
 ) {
-    let Some(array_length) = function.dfg.try_get_array_length(*array) else {
+    if function.dfg.try_get_array_length(*array).is_none() {
         // Nothing to do for slices
         return;
     };
 
-    let flattened_size = function.dfg.type_of_value(*array).flattened_size();
-    let element_size = flattened_size / array_length;
+    let element_size = function.dfg.type_of_value(*array).element_size();
     if element_size <= 1 {
         // Not a composite type
         return;

test_programs/execution_failure/empty_composite_array_get/Nargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "empty_composite_array_get"
+type = "bin"
+authors = [""]
+compiler_version = ">=0.32.0"
+
+[dependencies]

test_programs/execution_failure/empty_composite_array_get/Prover.toml

@@ -0,0 +1 @@
+empty_input = []

test_programs/execution_failure/empty_composite_array_get/src/main.nr

@@ -0,0 +1,5 @@
+fn main(empty_input: [(Field, Field); 0]) {
+    let empty_array: [(Field, Field); 0] = [];
+    let _ = empty_input[0];
+    let _ = empty_array[0];
+}