[Diag] Diagnostic adjustment for special DeclNames

The diagnostic warn_unqualified_access cannot exist with special
DeclNames and shall thus take an Identifier as parameter

Author: ahoppen

include/swift/AST/DiagnosticsSema.def

@@ -2618,7 +2618,7 @@ NOTE(add_self_to_type,none,
 
 WARNING(warn_unqualified_access,none,
         "use of %0 treated as a reference to %1 in %2 %3",
-        (DeclBaseName, DescriptiveDeclKind, DescriptiveDeclKind, DeclName))
+        (Identifier, DescriptiveDeclKind, DescriptiveDeclKind, DeclName))
 NOTE(fix_unqualified_access_member,none,
      "use 'self.' to silence this warning", ())
 NOTE(fix_unqualified_access_top_level,none,

lib/Sema/MiscDiagnostics.cpp

@@ -728,7 +728,7 @@ static void diagSyntacticUseRestrictions(TypeChecker &TC, const Expr *E,
       }
 
       TC.diagnose(DRE->getLoc(), diag::warn_unqualified_access,
-                  VD->getBaseName(), VD->getDescriptiveKind(),
+                  VD->getBaseName().getIdentifier(), VD->getDescriptiveKind(),
                   declParent->getDescriptiveKind(), declParent->getFullName());
       TC.diagnose(VD, diag::decl_declared_here, VD->getFullName());