[clang] [clang] Support 'this' position for lifetimebound attribute (PR #115021)

[Saleem Abdulrasool via cfe-commits]

================
@@ -730,7 +731,9 @@ class YAMLConverter {
     }
   }
 
-  void convertParams(const ParamsSeq &Params, FunctionInfo &OutInfo) {
+  std::optional<ParamInfo> convertParams(const ParamsSeq &Params,
+                                         FunctionInfo &OutInfo) {
----------------
compnerd wrote:

I suppose that is fine. I was suggesting that we keep the return type `void` and instead take an out parameter that is filled in. That would still keep the call site concise (IMO) and still make it easier to extend in the future (at least because there will be a design in place already which can be extended).

https://github.com/llvm/llvm-project/pull/115021