Add a test-suite based on CVE vulnerabilities

cve-test-suite/cve-2018-1000618.cpp

@@ -0,0 +1,16 @@
+
+// Reduced source code. Inspired by this fix:
+// https://github.com/EOSIO/eos/pull/4112/commits/ef62761c5e388880e8bb1bb41e8b512a5187f255
+
+#include <set>
+
+class C
+{
+    std::set<int> typedefs;
+    bool is_type(int type) const
+    {
+        if (typedefs.find(type) != typedefs.end())
+            return is_type(type); // BUG: endless recursion
+        return false;
+    }
+};