fix(codex): treat void as falsy

closes #789

Signed-off-by: azjezz <[email protected]>

Author: azjezz

crates/analyzer/tests/cases/issue_789.php

@@ -0,0 +1,11 @@
+<?php
+
+declare(strict_types=1);
+
+function returns_void(): void
+{
+}
+
+if (returns_void()) { // @mago-expect analysis:impossible-condition
+    echo 1;
+}

crates/analyzer/tests/mod.rs

@@ -506,6 +506,7 @@ test_case!(issue_766);
 test_case!(issue_776);
 test_case!(issue_782);
 test_case!(issue_785);
+test_case!(issue_789);
 
 #[test]
 fn test_all_test_cases_are_ran() {

crates/codex/src/ttype/atomic/mod.rs

@@ -713,7 +713,7 @@ impl TAtomic {
             TAtomic::Scalar(scalar) if scalar.is_falsy() => true,
             TAtomic::Array(array) if array.is_falsy() => true,
             TAtomic::Mixed(mixed) if mixed.is_falsy() => true,
-            TAtomic::Null => true,
+            TAtomic::Null | TAtomic::Void => true,
             _ => false,
         }
     }