C++: Add cpp/constant-comparison FP test cases after frontend update

Author: jketema

cpp/ql/test/query-tests/Likely Bugs/Arithmetic/PointlessComparison/PointlessComparison.expected

@@ -50,4 +50,9 @@
 | PointlessComparison.cpp:43:6:43:29 | ... >= ... | Comparison is always true because ... >> ... >= 140737488355327.5. |
 | PointlessComparison.cpp:44:6:44:28 | ... >= ... | Comparison is always true because ... >> ... >= 140737488355327.5. |
 | RegressionTests.cpp:57:7:57:22 | ... <= ... | Comparison is always true because * ... <= 4294967295. |
+| RegressionTests.cpp:131:17:131:25 | ... < ... | Comparison is always true because 43 <= ... + .... |
+| RegressionTests.cpp:135:26:135:52 | ... < ... | Comparison is always false because 16 >= ... * .... |
+| RegressionTests.cpp:140:50:140:61 | ... < ... | Comparison is always false because ... * ... >= 84. |
+| RegressionTests.cpp:154:21:154:31 | ... < ... | Comparison is always false because ... - ... >= 34. |
+| RegressionTests.cpp:154:21:154:31 | ... < ... | Comparison is always false because ... - ... >= 38. |
 | Templates.cpp:9:10:9:24 | ... <= ... | Comparison is always true because local <= 32767. |

cpp/ql/test/query-tests/Likely Bugs/Arithmetic/PointlessComparison/RegressionTests.cpp

@@ -124,3 +124,34 @@ void testTempObject() {
   f(&x);
   if (x > 0) {} // GOOD [NO LONGER REPORTED]
 }
+
+void staticAssert() {
+  static const int a = 42;
+  static const int b = 43;
+  static_assert(a < b + 0, ""); // GOOD [FALSE POSITIVE]
+}
+
+constexpr int global_1 = 42;
+constexpr int global_2 = global_1 < 2 * sizeof(int*) ? 43 : 2 * sizeof(int*); // GOOD [FALSE POSITIVE]
+
+static const int global_3 = 42;
+static const int global_4 = global_3 < 2 * sizeof(int*) ? 43 : 2 * sizeof(int*); // GOOD
+
+template<unsigned int p, unsigned int n, bool = ((2u * n) < p)>
+struct templateCompare : public templateCompare<p, 2u * n>  // GOOD [FALSE POSITIVE]
+{ };
+
+template< unsigned int p, unsigned int n>
+struct templateCompare< p, n, false>
+{
+  static const unsigned int v = n;
+};
+
+unsigned int templateCompare_x = templateCompare<42, 42>::v;
+
+template<int n>
+struct someType {
+  typedef someType<((n - 4) < 0 ? 0 : n - 4)> b;  // GOOD [FALSE POSITIVE]
+};
+
+someType<42>::b someType_x;