[clang] [clang] Update C++ DR status page (PR #218432)

[Corentin Jabot via cfe-commits]

cor3ntin wrote:

@zwuis the script checks that the test files and the issue status matches. it's rare that no test needs to be updated.  But if the script did not fail, it's good.

https://github.com/llvm/llvm-project/pull/218432