Convert two uses if fstat with sys::fs::status.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186560 91177308-0d34-0410-b5e6-96231b3b80d8
Remove dead code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186561 91177308-0d34-0410-b5e6-96231b3b80d8