[C++1z] Implement N3928: message in static_assert is optional.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211394 91177308-0d34-0410-b5e6-96231b3b80d8
Fix typo in r211394.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211395 91177308-0d34-0410-b5e6-96231b3b80d8
[C++1z] Add C++1z to the C++ status page.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211396 91177308-0d34-0410-b5e6-96231b3b80d8
Be less bold.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211397 91177308-0d34-0410-b5e6-96231b3b80d8
C++ status page: restore the convention of saying "SVN" until we reach a release.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211398 91177308-0d34-0410-b5e6-96231b3b80d8