[oneDNN] Add BFloat16 Specialization Functor for Mean Op
Hi @ezhulenev, can you please take a look at this PR? Thanks! Hi @ezhulenev, Can you please take a look at this PR? Thanks! Hi @ezhulenev - this PR got reverted, can you please point me to the error so we can fix it? Thanks.
Currently BFloat16 Mean Op causes BFloat16 accumulation which may result in incorrect output. This prevents Mean to be used with the lower BFloat16 precision. This PR:

1. Just like the existing implementation of the Sum op, ensures BFloat16 Mean accumulation happens in FP32 by adding a Casting Specialization registration.
2. Adds Benchmark and Kernel tests to verify the implementation.
3. Adds Mean back to the Infer List from Deny List and fixes a typo in the Infer List initialization.