[clang] [Clang] Reapply CWG2369 "Ordering between constraints and substitution" (PR #122423)

[via cfe-commits]

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@@ -10506,7 +10506,8 @@ class Sema final : public SemaBase {
       FunctionTemplateDecl *FunctionTemplate, ArrayRef<QualType> ParamTypes,
       ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet,
       ConversionSequenceList &Conversions, bool SuppressUserConversions,
-      CXXRecordDecl *ActingContext = nullptr, QualType ObjectType = QualType(),
+      bool SkipUserDefinedConversions, CXXRecordDecl *ActingContext = nullptr,
+      QualType ObjectType = QualType(),
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cor3ntin wrote:

SuppressUserConversions and SkipUserDefinedConversions is going to be super confusing. 
Ca=n we replace both booleans by a single enum, and add comments? 

https://github.com/llvm/llvm-project/pull/122423