Missing do_cleanups in ada_make_symbol_completion_list.

This results in an internal-warning when trying the completion
when in Ada mode:

    (gdb) b simple<TAB>
    /[...]/cleanups.c:265: internal-warning: restore_my_cleanups has found a stale cleanup
    A problem internal to GDB has been detected,
    further debugging may prove unreliable.
    Quit this debugging session? (y or n)

gdb/ChangeLog:

        * ada-lang.c (ada_make_symbol_completion_list): Make sure
        all cleanups are done before returning from this function.

gdb/testsuite/ChangeLog:

        * gdb.ada/complete.exp: Add test verifying completion using
        the "tab" key.

1 files changed, 16 insertions, 1 deletions

diff --git a/gdb/testsuite/gdb.ada/complete.exp b/gdb/testsuite/gdb.ada/complete.exp
index 973e20b8e14..91859085e06 100644
--- a/gdb/testsuite/gdb.ada/complete.exp
+++ b/gdb/testsuite/gdb.ada/complete.exp
@@ -175,4 +175,19 @@ test_gdb_complete "pck." \
 test_gdb_complete "<pck__my" \
                   "p <pck__my_global_variable>"
 
-
+# Very simple completion, but using the interactive form, this time.
+# The verification we are trying to make involves the event loop,
+# and using the "complete" command is not sufficient to reproduce
+# the original problem.
+set test "interactive complete 'print some'"
+send_gdb "print some\t"
+gdb_test_multiple "" "$test" {
+    -re "^print some_local_variable $" {
+        send_gdb "\n"
+        gdb_test_multiple "" "$test" {
+            -re " = 1$eol$gdb_prompt $" {
+                pass "$test"
+            }
+        }
+    }
+}