Eliminate FutureWarning from numpy (#6703)

Casting `diagonal_slice` to tuple eliminates a FutureWarning from numpy that could cause an error down the line.

Eliminate FutureWarning from numpy (#6703)
bb2daf97 · Rodrigo Luger · Thomas Wiecki · 9feed786 · bb2daf97
--- a/theano/tensor/basic.py
+++ b/theano/tensor/basic.py
@@ -6608,7 +6608,7 @@ class AllocDiag(Op):
                           idxs + np.maximum(0, offset)])

        # Fill in final 2 axes with x
-        result[diagonal_slice] = x
+        result[tuple(diagonal_slice)] = x

        if len(x.shape) > 1:
            # Re-order axes so they correspond to diagonals at axis1, axis2