C++: Tweak a comment in simple range analysis

Co-authored-by: Geoffrey White <[email protected]>

Author: paldepind

cpp/ql/test/library-tests/rangeanalysis/SimpleRangeAnalysis/test.c

@@ -335,7 +335,7 @@ int test_mult05(int a, int b) {
 
 // Tests for shift operators.
 unsigned long long test_shift(unsigned long long a) {
-  // `odd` is the largest odd integer that can be represented by a double.
+  // `odd` is the largest odd integer that can be precisely represented by a double.
   unsigned long long odd = 9007199254740992 - 1; // 2^53 - 1
   // Shifting right by by 1 give an upper bound that is half of `odd` rounded down.
   unsigned long long shifted = odd >> 1;