[clang] Add Clang attribute to ensure that fields are initialized explicitly (PR #102040)

[Aaron Ballman via cfe-commits]

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@@ -2318,6 +2318,10 @@ def err_init_list_bad_dest_type : Error<
 def warn_cxx20_compat_aggregate_init_with_ctors : Warning<
   "aggregate initialization of type %0 with user-declared constructors "
   "is incompatible with C++20">, DefaultIgnore, InGroup<CXX20Compat>;
+def warn_cxx20_compat_requires_explicit_init_non_aggregate : Warning<
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AaronBallman wrote:

Rewrap for 80 col limit?

https://github.com/llvm/llvm-project/pull/102040