Update Aspectator and add one more test case

tests/input/complex.c

@@ -0,0 +1,3 @@
+void test(int a, int b, int c) {
+  int x = __builtin_mul_overflow (a, b, &c);
+}

tests/test_complex.py

@@ -0,0 +1,15 @@
+import unittest
+import utils
+
+
+class TestComplex(utils.CIFTestCase):
+    # Test for REALPART_EXPR and IMAGPART_EXPR - only up to instrumentation stage.
+    # These nodes represent respectively the real and the imaginary parts of complex numbers (their sole argument).
+    # Compilation stage with "src" back-end require support for these expressions in c-backend.
+    def test_realpart_expr(self):
+        self.cif.run(cif_input='input/complex.c', aspect='aspect/empty.aspect', stage='instrumentation')
+        self.check_cif_status()
+
+
+if __name__ == '__main__':
+    unittest.main()