[clang] [BoundsSafety] WIP: Make 'counted_by' work for pointer fields; late parsing for 'counted_by' on decl attr position (PR #87596)

[Dan Liew via cfe-commits]

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@@ -1599,6 +1599,13 @@ defm double_square_bracket_attributes : BoolFOption<"double-square-bracket-attri
   LangOpts<"DoubleSquareBracketAttributes">, DefaultTrue, PosFlag<SetTrue>,
  NegFlag<SetFalse>>;
 
+defm experimental_late_parse_attributes : BoolFOption<"experimental-late-parse-attributes",
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delcypher wrote:

@rapidsna FYI. Here's a sketch of an experimental late parsing flag. It's not quite done yet and I think it's big enough that it deserves it's own PR. Just pushing it here to give you an idea of my plans

https://github.com/llvm/llvm-project/pull/87596