C++: Add 'cpp/use-of-unique-pointer-after-lifetime-ends' FP.

Author: MathiasVP

cpp/ql/test/query-tests/Security/CWE/CWE-416/semmle/tests/UseOfUniquePtrAfterLifetimeEnds/UseOfUniquePointerAfterLifetimeEnds.expected

@@ -9,3 +9,4 @@
 | test.cpp:177:16:177:16 | call to operator* | The underlying unique pointer object is destroyed after the call to 'operator*' returns. |
 | test.cpp:177:36:177:36 | call to operator* | The underlying unique pointer object is destroyed after the call to 'operator*' returns. |
 | test.cpp:179:11:179:11 | call to operator* | The underlying unique pointer object is destroyed after the call to 'operator*' returns. |
+| test.cpp:209:29:209:31 | call to get | The underlying unique pointer object is destroyed after the call to 'get' returns. |

cpp/ql/test/query-tests/Security/CWE/CWE-416/semmle/tests/UseOfUniquePtrAfterLifetimeEnds/test.cpp

@@ -203,4 +203,12 @@ void test2(bool b1, bool b2) {
   auto s11 = b2 ? nullptr : sRefRef.get(); // GOOD
   const S* s12;
   s12 = sRefRef.get(); // GOOD
+}
+
+void test_convert_to_bool() {
+  bool b = get_unique_ptr().get(); // GOOD [FALSE POSITIVE]
+
+  if(get_unique_ptr().get()) { // GOOD
+
+  }
 }