C++: Accept test changes after making the exprMightOverFlow predicates more sound.

Author: MathiasVP

cpp/ql/test/query-tests/Security/CWE/CWE-190/semmle/extreme/ArithmeticWithExtremeValues.expected

@@ -3,4 +3,5 @@
 | test.c:50:3:50:5 | sc3 | $@ flows to here and is used in arithmetic, potentially causing an overflow. | test.c:49:9:49:16 | 127 | Extreme value |
 | test.c:59:3:59:5 | sc6 | $@ flows to here and is used in arithmetic, potentially causing an overflow. | test.c:58:9:58:16 | 127 | Extreme value |
 | test.c:63:3:63:5 | sc8 | $@ flows to here and is used in arithmetic, potentially causing an underflow. | test.c:62:9:62:16 | - ... | Extreme value |
+| test.c:75:3:75:5 | sc1 | $@ flows to here and is used in arithmetic, potentially causing an overflow. | test.c:74:9:74:16 | 127 | Extreme value |
 | test.c:124:9:124:9 | x | $@ flows to here and is used in arithmetic, potentially causing an overflow. | test.c:118:17:118:23 | 2147483647 | Extreme value |

cpp/ql/test/query-tests/Security/CWE/CWE-190/semmle/extreme/test.c

@@ -72,7 +72,7 @@ void test_negatives() {
   signed char sc1, sc2, sc3, sc4, sc5, sc6, sc7, sc8;
 
   sc1 = CHAR_MAX;
-  sc1 += 0; // GOOD
+  sc1 += 0; // GOOD [FALSE POSITIVE]
   sc1 += -1; // GOOD
   sc2 = CHAR_MIN;
   sc2 += -1; // BAD [NOT DETECTED]