[clang-tools-extra] [clang-reorder-fields] Support designated initializers (PR #142150)

[Clement Courbet via cfe-commits]

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@@ -81,18 +83,52 @@ getNewFieldsOrder(const RecordDecl *Definition,
   return NewFieldsOrder;
 }
 
+struct ReorderedStruct {
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legrosbuffle wrote:

If you can pull out this refactoring (`ReorderedStruct` + `addRepacement`) to a separate commit that'd be great.

https://github.com/llvm/llvm-project/pull/142150