[lit] Remove --single-process option (use -j1 instead)

Remove `--single-process` command line option. Use `-j1` instead.

Also see commit: 96adb78b120b6aa9739eb714534dc8e819f7bc52

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354073 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed