[clang] [clang] Add -Wmissing-designated-field-initializers (PR #81364)

[Vadim D. via cfe-commits]

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@@ -120,6 +120,10 @@ Non-comprehensive list of changes in this release
 New Compiler Flags
 ------------------
 
+- ``-Wmissing-designated-field-initializers``, grouped under ``-Wmissing-designated-field-initializers``.
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vvd170501 wrote:

Would it be ok to also add this patch to the 18.x release branch?
It would be nice to have a way to keep old behavior of the m-f-i check when upgrading from Clang 16/17 to 18.

https://github.com/llvm/llvm-project/pull/81364