Added test for issue #7

Author: cmaglie

testsuite/testdata/test_issue_7.cpp

@@ -0,0 +1,9 @@
+// https://github.com/arduino/arduino-preprocessor/issues/7
+
+#line 1 "issue_7.ino"
+
+int a; int b=f();
+
+int f() {
+  return 1;
+}