patch 9.1.0335: String interpolation fails for List type

Problem:  String interpolation fails for List type
Solution: use implicit string(list) for string interpolation and :put =
          (Yegappan Lakshmanan)

related: #14529
closes: #14556

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/proto/eval.pro b/src/proto/eval.pro
index 47fd83d..1c2d05d 100644
--- a/src/proto/eval.pro
+++ b/src/proto/eval.pro
@@ -14,9 +14,9 @@
 void clear_evalarg(evalarg_T *evalarg, exarg_T *eap);
 int skip_expr(char_u **pp, evalarg_T *evalarg);
 int skip_expr_concatenate(char_u **arg, char_u **start, char_u **end, evalarg_T *evalarg);
-char_u *typval2string(typval_T *tv, int convert);
-char_u *eval_to_string_eap(char_u *arg, int convert, exarg_T *eap, int use_simple_function);
-char_u *eval_to_string(char_u *arg, int convert, int use_simple_function);
+char_u *typval2string(typval_T *tv, int join_list);
+char_u *eval_to_string_eap(char_u *arg, int join_list, exarg_T *eap, int use_simple_function);
+char_u *eval_to_string(char_u *arg, int join_list, int use_simple_function);
 char_u *eval_to_string_safe(char_u *arg, int use_sandbox, int keep_script_version, int use_simple_function);
 varnumber_T eval_to_number(char_u *expr, int use_simple_function);
 typval_T *eval_expr(char_u *arg, exarg_T *eap);