Revert r344529 "Implement the first part of the calendar support for C++20"
Revert r344535 "Wrap up the new chrono literals in an #ifdef..."
Revert r344546 "Mark a couple of test cases as 'C++17-only'..."

Some of the buildbot failures were masked by another error,
and this one was probably missed.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@344580 91177308-0d34-0410-b5e6-96231b3b80d8
183 files changed