Eradicate tabs

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@189808 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a typo in the status for <optional>


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@189809 91177308-0d34-0410-b5e6-96231b3b80d8
Updated the synopsis for weak_ptr<T>::owner_before to match the code. No code changes.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@189812 91177308-0d34-0410-b5e6-96231b3b80d8