chore(test): add tests for unconstrained main recursion (#8551)

Co-authored-by: Tom French <15848336+TomAFrench@users.noreply.github.com>

Author: michaeljklein

test_programs/execution_success/brillig_recursive_main/Nargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "brillig_recursive_main"
+type = "bin"
+authors = [""]
+
+[dependencies]

test_programs/execution_success/brillig_recursive_main/Prover.toml

@@ -0,0 +1,3 @@
+x = "3"
+
+return = true

test_programs/execution_success/brillig_recursive_main/src/main.nr

@@ -0,0 +1,7 @@
+unconstrained fn main(x: u32) -> pub bool {
+    if x == 0 {
+        true
+    } else {
+        main(x - 1)
+    }
+}

test_programs/execution_success/brillig_recursive_main/stdout.txt

@@ -0,0 +1 @@
+[brillig_recursive_main] Circuit output: Field(1)

test_programs/execution_success/brillig_recursive_main_indirect/Nargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "brillig_recursive_main_indirect"
+type = "bin"
+authors = [""]
+
+[dependencies]

test_programs/execution_success/brillig_recursive_main_indirect/Prover.toml

@@ -0,0 +1,3 @@
+x = "10"
+
+return = true

test_programs/execution_success/brillig_recursive_main_indirect/src/main.nr

@@ -0,0 +1,15 @@
+unconstrained fn foo(x: u32, f: unconstrained fn(u32) -> bool) -> bool {
+    if f(x - 1) & (x > 1) {
+        f(x - 2)
+    } else {
+        x < 2
+    }
+}
+
+unconstrained fn main(x: u32) -> pub bool {
+    if x == 0 {
+        true
+    } else {
+        foo(x, main)
+    }
+}