Merging r338942:

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r338942 | rsmith | 2018-08-04 03:02:00 +0200 (Sat, 04 Aug 2018) | 1 line

[www] Update cxx_status and cxx_dr_status now that Clang 7 has branched.
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git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_70@339002 91177308-0d34-0410-b5e6-96231b3b80d8