onnxruntime

Rework CDist (#3393)

* Make CDist faster via Eigen squaredNorma and GEMM.
  * Add call to abs() as the GEMM output may differ slightly due to floating point accuracy and result in a negative distance which returns NaN if sqrt() is applied to it.
* Update math::Gemm to use the type for alpha and beta instead of hardcoding to float. Matches the GemmEx definition.
* Provide Eigen based replication of the GEMM call on x86 if T=double.
* Make test model data deterministic.
* Do the GEMM first so we can avoid potentially subtracting two numbers that are very close to each other.