fix #H2588 - turn order alternation bug

From a bug report, when the hero has
precisely 24 movement points, fast monsters will move twice and then the
hero will move twice, instead of being interleaved.  The hero will get 24
additonal movement points approximately one turn out of three when wearing
speed boots (or when using spell of haste self or potion of speed) and can
also get 18 additional points twice in succession, with a net of 24 after
12 of them are used on the first turn.  But hero might not be starting at
zero at the time, so I'm not sure how often this is actually noticeable.

     He apparently got a report about this for <some variant> and had some
user-contributed instrumentation in place that made it easier to replicate.
This fix is the one he suggested.

doc/fixes35.0

@@ -840,6 +840,8 @@ declining to attack a peaceful monster via movement used up nutrition even
 declining to attack a peaceful monster via kicking woke nearby monsters and
 	scuffed engraving at hero's location even though no action took place
 make hero be immune from stinking cloud damage during successful prayer
+very fast hero would sometimes take two consecutive moves with very fast
+	monsters then getting two moves, instead of interleaving the activity
 
 
 Platform- and/or Interface-Specific Fixes

src/allmain.c

@@ -97,7 +97,7 @@ boolean resuming;
 		context.mon_moving = TRUE;
 		do {
 		    monscanmove = movemon();
-		    if (youmonst.movement > NORMAL_SPEED)
+		    if (youmonst.movement >= NORMAL_SPEED)
 			break;	/* it's now your turn */
 		} while (monscanmove);
 		context.mon_moving = FALSE;