- Test runner will also check for leaks.

- `write` of qoi would leak memory.
- Issue when having an empty `Path` or just "."
- `set_env` would leak memory.

test/unit/stdlib/string.c3

@@ -3,6 +3,7 @@ module string_test;
 fn void test_clear() @test
 {
 	DString s = dstring::new_with_capacity(32);
+	defer s.free();
 	assert(s.len() == 0);
 	assert(s.capacity() == 32);
 	s.append_repeat('x', 63);