Add Rust target

spec/test_user_code.rs

@@ -0,0 +1,13 @@
+use testparser::*;
+
+fn main() {
+    let mut context = p_context_new(b"abcdef");
+    assert_eq!(P_SUCCESS, p_parse(&mut context));
+    println!("pass1");
+    p_context_delete(context);
+
+    let mut context = p_context_new(b"abcabcdef");
+    assert_eq!(P_SUCCESS, p_parse(&mut context));
+    println!("pass2");
+    p_context_delete(context);
+}