Merge pull request #28038 from davidungar/rdar-56760957-dont-do-ide-lookups-into-inactive-clauses

[SourceKit NameLookup] Don't walk into inactive clauses.

include/swift/AST/NameLookup.h

@@ -627,6 +627,8 @@ public:
     return Mem;
   }
 
+  static bool areInactiveIfConfigClausesSupported();
+
 private:
   static ast_scope::ASTSourceFileScope *createScopeTree(SourceFile *);
 };