Add test

Author: kastiglione

lldb/test/API/lang/cpp/extern_c/main.cpp

@@ -8,7 +8,7 @@ extern "C"
 
 int foo()
 {
-    puts("foo");
+    puts("foo"); //% self.expect("image lookup -v -a $pc", substrs=['mangled = "foo"'])
     return 2;
 }