Add boxed specializations of BytesBuiltin.FindNode

Prior to this commit, pytz.timezone fails with an
UnsupportedSpecializationException because it calls bytes.find with a
(boxed) Long rather than an int for the argument `start`. To fix this,
I've added new specializations that expect a Number, which should allow
this method to work when passed in boxed number types.

Author: Zach Olstein

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/bytes/BytesBuiltins.java

@@ -704,11 +704,21 @@ int find(VirtualFrame frame, PIBytesLike self, Object sub, int start, @SuppressW
             return find(frame, self, sub, start, getLength(self.getSequenceStorage()));
         }
 
+        @Specialization
+        int find (VirtualFrame frame, PIBytesLike self, Object sub, Number start, @SuppressWarnings("unused") PNone end) {
+            return find(frame, self, sub, start, getLength(self.getSequenceStorage()));
+        }
+
         @Specialization
         int find(VirtualFrame frame, PIBytesLike self, Object sub, int start, int ending) {
             return getFindNode().execute(frame, self, sub, start, ending);
         }
 
+        @Specialization
+        int find(VirtualFrame frame, PIBytesLike self, Object sub, Number start, Number ending) {
+            return getFindNode().execute(frame, self, sub, start, ending);
+        }
+
         private BytesNodes.FindNode getFindNode() {
             if (findNode == null) {
                 CompilerDirectives.transferToInterpreterAndInvalidate();