Don't prompt field names for tuples at the REPL

Author: Lilith Hafner

stdlib/REPL/src/REPLCompletions.jl

@@ -202,7 +202,7 @@ function complete_symbol(sym::String, @nospecialize(ffunc), context_module::Modu
                 t = typeof(t.parameters[1])
             end
             # Only look for fields if this is a concrete type
-            if isconcretetype(t)
+            if isconcretetype(t) && !(t <: Tuple)
                 fields = fieldnames(t)
                 for field in fields
                     s = string(field)