Fixed MDEV-7314: Deadlock when doing insert-select with Aria

mysql-test/suite/maria/insert_select.result:
  Added test case
mysql-test/suite/maria/insert_select.test:
  Added test case
mysys/thr_lock.c:
  Ensure we don't allow concurrent_insert when a read_no_write lock is in use

mysql-test/suite/maria/insert_select.result

+drop table if exists t1;
+Warnings:
+Note	1051	Unknown table 'test.t1'
+#
+# MDEV-7314
+# Concurrent "INSERT INTO table SELECT MAX(id)+1 FROM table" are
+# hitting deadlocks on Aria tables using ROW_FORMAT=PAGE
+#
+create table t1 (pk int primary key) engine=Aria;
+insert into t1 values (1);
+insert into t1 select sleep(2)+1 from t1;
+insert into t1 select 2 from t1;
+select * from t1;
+pk
+1
+2
+drop table t1;

mysql-test/suite/maria/insert_select.test

+-- source include/have_maria.inc
+--source include/have_binlog_format_statement.inc
+
+drop table if exists t1;
+
+--echo #
+--echo # MDEV-7314
+--echo # Concurrent "INSERT INTO table SELECT MAX(id)+1 FROM table" are
+--echo # hitting deadlocks on Aria tables using ROW_FORMAT=PAGE
+--echo #
+
+create table t1 (pk int primary key) engine=Aria;
+insert into t1 values (1);
+
+send insert into t1 select sleep(2)+1 from t1;
+
+--connect (con1,localhost,root,,)
+
+--error 0,1062
+insert into t1 select 2 from t1;
+
+--connection default
+--error 0,1062
+--reap
+
+select * from t1;
+drop table t1;

mysys/thr_lock.c

@@ -833,7 +833,8 @@ thr_lock(THR_LOCK_DATA *data, THR_LOCK_INFO *owner, ulong lock_wait_timeout)
 
       if (((lock_type == TL_WRITE_ALLOW_WRITE ||
            (lock_type == TL_WRITE_CONCURRENT_INSERT &&
-             lock->allow_multiple_concurrent_insert)) &&
+             lock->allow_multiple_concurrent_insert &&
+            !lock->read_no_write_count)) &&
            ! lock->write_wait.data &&
            lock->write.data->type == lock_type) ||
           has_old_lock(lock->write.data, data->owner))