(MaximKalininMS) Fix Reshape Fusion and Crash in Reshape (#3777)
* Fix a crash in Reshape
Reshape doesn't handle 0 input dimension properly, which leads to a
division by zero
* Fix reshape fusion
https://github.com/microsoft/onnxruntime/pull/3554 introduced a bug:
initializers can now come before Shape->Gather->Unsqueeze chains; if
those initializers have more than 1 element, expected dimensions in the
chains are now incorrect.
Authored-by: Max Kalinin <makalini@microsoft.com>