C++: Add testcase with INTMAX_MIN.

Author: MathiasVP

cpp/ql/test/query-tests/Security/CWE/CWE-190/semmle/tainted/test5.cpp

@@ -29,4 +29,14 @@ void useTaintedIntWithGuard() {
 	if(imaxabs(tainted) <= 100) {
 		int product = tainted * tainted; // GOOD: can't underflow/overflow
 	}
+}
+
+#define INTMAX_MIN (-0x7fffffffffffffff - 1)
+
+void useTaintedIntWithGuardIntMaxMin() {
+	intmax_t tainted = getTaintedInt();
+
+	if(imaxabs(tainted) <= INTMAX_MIN) {
+		int product = tainted * tainted; // BAD: imaxabs(INTMAX_MIN) == INTMAX_MIN [NOT DETECTED]
+	}
 }