gdb: allow enumeration constants as second operand of BINOP_REPEAT

This patch adds support for TYPE_CODE_ENUM values to be supplied
as right-hand side operand of the BINOP_REPEAT (@) operator. The
following should now work:

enum {
  sz = 17
};

int
main ()
{
  int arr[sz + 1] = { 0 };
  return 0; /* line 9 here */
}

(gdb) b 9
(gdb) r
(gdb) p arr@sz
$1 = {0 <repeats 17 times>}
(gdb)

A couple of tests is also included in this patch to demonstrate that it is
working as intended.

gdb/Changelog:

2016-04-01  Artemiy Volkov  <artemiyv@acm.org>

	PR gdb/19820
	* eval.c (evaluate_subexp_standard): Allow TYPE_CODE_ENUM to be
        the type of BINOP_REPEAT's second operand.

gdb/testsuite/Changelog:

2016-04-01  Artemiy Volkov  <artemiyv@acm.org>

	PR gdb/19820
	* gdb.base/printcmds.exp: Add artificial arrays tests.

1 files changed, 2 insertions, 1 deletions

diff --git a/gdb/eval.c b/gdb/eval.c
index 78ad946..5d32a3c 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -2427,7 +2427,8 @@ evaluate_subexp_standard (struct type *expect_type,
       if (noside == EVAL_SKIP)
 	goto nosideret;
       type = check_typedef (value_type (arg2));
-      if (TYPE_CODE (type) != TYPE_CODE_INT)
+      if (TYPE_CODE (type) != TYPE_CODE_INT
+          && TYPE_CODE (type) != TYPE_CODE_ENUM)
 	error (_("Non-integral right operand for \"@\" operator."));
       if (noside == EVAL_AVOID_SIDE_EFFECTS)
 	{