Use pre-increment also for native types

Now that we use pre-increment on enums, it
make sense, for code style uniformity, to
swith to pre-increment also for native types,
although there is no speed difference.

No functional change.

src/evaluate.cpp

@@ -288,7 +288,7 @@ namespace Eval {
     const int MaxSlope = 30;
     const int Peak = 1280;
 
-    for (int t = 0, i = 1; i < 100; i++)
+    for (int t = 0, i = 1; i < 100; ++i)
     {
         t = std::min(Peak, std::min(int(0.4 * i * i), t + MaxSlope));