Use shim executable sccache-cl as the compiler instead of sccache cl (#33745)
Summary:
CMake only views the first item of `CC` and `CXX` as executable. So calling `sccache.exe` directly won't work. Using a shim executable resolves this problem.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/33745
Differential Revision: D20100397
Pulled By: soumith
fbshipit-source-id: 3a130d30dd548b7c2e726c064e66ae4fccb30c44
