[te][reapply] Add fast log approximation based on sleef (#49575)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/49575
This is a fast log implementations
benchmark:
```
buck run mode/opt //caffe2/benchmarks/cpp/tensorexpr:tensorexpr_bench -c 'fbcode.caffe2_gpu_type=none'
```
Test Plan: buck test mode/no-gpu //caffe2/test/cpp/tensorexpr:tensorexpr -- *.fastLogFloat
Reviewed By: bertmaher
Differential Revision: D25627157
fbshipit-source-id: a4920f4f4005ce617d372b375e790ca966275cd9
