Improve unit tests of zeta, polygamma, and digamma
Improve unit tests of zeta, polygamma, and digamma

pasuka/eigen,pasuka/eigen,ROCmSoftwarePlatform/hipeigen,ritsu1228/eigen,ritsu1228/eigen,ritsu1228/eigen,ROCmSoftwarePlatform/hipeigen,ROCmSoftwarePlatform/hipeigen,pasuka/eigen,pasuka/eigen,pasuka/eigen,ritsu1228/eigen,ROCmSoftwarePlatform/hipeigen,ritsu1228/eigen