compute foreign object size when recalculating the new slice indices.

Author: cosminbasca

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/foreign/AccessForeignItemNodes.java

@@ -95,26 +95,7 @@ protected int getForeignSize(TruffleObject object, Node getSizeNode, PForeignToP
         }
 
         protected SliceInfo materializeSlice(PSlice idxSlice, TruffleObject object, Node getSizeNode, PForeignToPTypeNode foreign2PTypeNode) throws UnsupportedMessageException {
-
-            // determine start
-            boolean isStartMissing = false;
-            int start = idxSlice.getStart();
-            if (start == PSlice.MISSING_INDEX) {
-                start = 0;
-                isStartMissing = true;
-            }
-
-            // determine stop
-            int end = idxSlice.getStop();
-            int foreignSize = -1;
-            if (end == PSlice.MISSING_INDEX) {
-                foreignSize = getForeignSize(object, getSizeNode, foreign2PTypeNode);
-                end = foreignSize;
-            } else if (isStartMissing) {
-                foreignSize = getForeignSize(object, getSizeNode, foreign2PTypeNode);
-            }
-
-            // determine length (foreignSize is only required if start or stop is missing)
+            int foreignSize = getForeignSize(object, getSizeNode, foreign2PTypeNode);
             return idxSlice.computeIndices(foreignSize);
         }
     }