C++: Add comments about the temporary exclusions.

Author: geoffw0

cpp/ql/src/Best Practices/Unused Entities/UnusedLocals.ql

@@ -58,9 +58,9 @@ where
   not exists(AsmStmt s | f = s.getEnclosingFunction()) and
   not v.getAnAttribute().getName() = "unused" and
   not any(ErrorExpr e).getEnclosingFunction() = f and // unextracted expr may use `v`
-  not exists(Literal l |
+  not exists(Literal l | // this case can be removed when the `myFunction2( [obj](){} );` test case doesn't depend on this exclusion
     l.getEnclosingFunction() = f and
     not exists(l.getValue())
   ) and
-  not any(ConditionDeclExpr cde).getEnclosingFunction() = f
+  not any(ConditionDeclExpr cde).getEnclosingFunction() = f // this case can be removed when the `if (a = b; a)` test case doesn't depend on this exclusion
 select v, "Variable " + v.getName() + " is not used"