[pushed] [gdb/testsuite] Fix gdb.tui/main.exp without TUI

[Tom de Vries]

With a build with --disable-tui, we get:
...
(gdb) PASS: gdb.tui/main.exp: set interactive-mode off
maint set tui-left-margin-verbose on^M
Undefined maintenance set command: "tui-left-margin-verbose on".  \
  Try "help maintenance set".^M
(gdb) FAIL: gdb.tui/main.exp: maint set tui-left-margin-verbose on
...

Fix this by adding the missing "require allow_tui_tests".

Tested on x86_64-linux.
---
 gdb/testsuite/gdb.tui/main.exp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/gdb/testsuite/gdb.tui/main.exp b/gdb/testsuite/gdb.tui/main.exp
index 9cd3ce8a96d..8664206e30b 100644
--- a/gdb/testsuite/gdb.tui/main.exp
+++ b/gdb/testsuite/gdb.tui/main.exp
@@ -15,6 +15,8 @@
 
 # Test that "file" shows "main".
 
+require allow_tui_tests
+
 tuiterm_env
 
 standard_testfile tui-layout.c

base-commit: dffcf6e5e60f28fc1df041ea89c4d5b8b5d843cd
-- 
2.35.3