add Half support for unary ops on CPU (#98493)
Add Half support for log_sigmoid and some unary ops on CPU, including sinc, acosh, asinh, atanh, digamma, trigamma, rsqrt, acos, asin, atan, ceil, cos, erf, erfc, erfinv, exp, expml, floor, log, log10, log1p, log2, i0, round, sin, sqrt, tan, tanh, trunc, lgamma.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/98493
Approved by: https://github.com/jgong5, https://github.com/mingfeima, https://github.com/ngimel
