[clang-tools-extra] [clang-tidy]Fix PreferMemberInitializer false positive for reassignment (PR #70316)

[Piotr Zegar via cfe-commits]

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@@ -156,6 +153,49 @@ void PreferMemberInitializerCheck::check(
   const CXXRecordDecl *Class = Ctor->getParent();
   bool FirstToCtorInits = true;
 
+  std::map<const FieldDecl *, AssignedLevel> AssignedFields{};
+
+  // Checks if Field is initialised using a field that will be initialised after
+  // it.
+  // TODO: Probably should guard against function calls that could have side
+  // effects or if they do reference another field that's initialized before
+  // this field, but is modified before the assignment.
+  auto UpdateAssignmentLevel = [Ctor, &AssignedFields](const FieldDecl *Field,
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PiotrZSL wrote:

Move this lambda to separate method, this method is already big.

https://github.com/llvm/llvm-project/pull/70316