Revert "always peel the first iteration (like PyPy)"

This reverts commit 9c3eeddf3713916a4a4358dbb4cc8dc66cba3722.

Author: timfel

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/control/ForNode.java

@@ -185,10 +185,7 @@ public void executeVoid(VirtualFrame frame) {
         }
         frame.setObject(iteratorSlot, iterator.execute(frame));
         try {
-            if (((ForRepeatingNode) loopNode.getRepeatingNode()).executeRepeating(frame)) {
-                // manually peel the first iteration
-                loopNode.executeLoop(frame);
-            }
+            loopNode.executeLoop(frame);
         } finally {
             frame.setObject(iteratorSlot, null);
         }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/control/WhileNode.java

@@ -81,9 +81,6 @@ public CastToBooleanNode getCondition() {
 
     @Override
     public void executeVoid(VirtualFrame frame) {
-        if (((WhileRepeatingNode) loopNode.getRepeatingNode()).executeRepeating(frame)) {
-            // manually peel the first iteration
-            loopNode.executeLoop(frame);
-        }
+        loopNode.executeLoop(frame);
     }
 }