Extends OpInfo architecture with reference inputs, adds them for elementwise binary operators
This PR extends our OpInfo test architecture with "reference inputs," an optional expansion of typical sample inputs that allows for more thorough testing. Currently only the elementwise binary operations implement an extended set of reference inputs. This PR also cleans up some smaller OpInfo-related issues, including several bugs, and it identified https://github.com/pytorch/pytorch/issues/74279.
A reference inputs function can be specified for an OpInfo by filling in its "reference_inputs_func" metadata. If this is done it's recommended that the reference inputs function first call the sample inputs function, then produce additional sample inputs. See `reference_inputs_elementwise_binary` for an example of this pattern.
In addition to implementing reference inputs for the elementwise binary operations, this PR improves their consistency and simplifies how their metadata is represented. The great majority now use a generic sample input function, and those that want extensions start by calling the generic sample input function and then adding additional samples. This removes many older sample input functions. The BinaryUfuncInfo subclass also now allows specifying scalar support more precisely, and reference inputs and error inputs are generated based on this metadata to ensure it's correct.
cc @kshitij12345 @pmeier @zou3519 @Chillee
Pull Request resolved: https://github.com/pytorch/pytorch/pull/74280
Approved by: https://github.com/ngimel
