patch 8.0.0864: cannot specify the name of a terminal

Problem:    Cannot specify the name of a terminal.
Solution:   Add the "term_name" option. (Yasuhiro Matsumoto, closes #1936)
diff --git a/src/channel.c b/src/channel.c
index b19f089..801e370 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -4391,6 +4391,18 @@
 		    return FAIL;
 		}
 	    }
+	    else if (STRCMP(hi->hi_key, "term_name") == 0)
+	    {
+		if (!(supported & JO2_TERM_NAME))
+		    break;
+		opt->jo_set2 |= JO2_TERM_NAME;
+		opt->jo_term_name = get_tv_string_chk(item);
+		if (opt->jo_term_name == NULL)
+		{
+		    EMSG2(_(e_invarg2), "term_name");
+		    return FAIL;
+		}
+	    }
 	    else if (STRCMP(hi->hi_key, "waittime") == 0)
 	    {
 		if (!(supported & JO_WAITTIME))