[Clang][Sema] Make UnresolvedLookupExprs in class scope explicit specializations instantiation dependent (#100392)

A class member named by an expression in a member function that may instantiate to a static _or_ non-static member is represented by a `UnresolvedLookupExpr` in order to defer the implicit transformation to a class member access expression until instantiation. Since `ASTContext::getDecltypeType` only creates a `DecltypeType` that has a `DependentDecltypeType` as its canonical type when the operand is instantiation dependent, and since we do not transform types unless they are instantiation dependent, we need to mark the `UnresolvedLookupExpr` as instantiation dependent in order to correctly build a `DecltypeType` using the expression as its operand with a `DependentDecltypeType` canonical type. Fixes #99873. 

1 files changed, 1 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index bab32b9..1da16d6 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -1219,7 +1219,7 @@ Corrected:
   return NameClassification::OverloadSet(UnresolvedLookupExpr::Create(
       Context, Result.getNamingClass(), SS.getWithLocInContext(Context),
       Result.getLookupNameInfo(), ADL, Result.begin(), Result.end(),
-      /*KnownDependent=*/false));
+      /*KnownDependent=*/false, /*KnownInstantiationDependent=*/false));
 }
 
 ExprResult