Issue type:

[ ] question
[x] bug report
[ ] feature request
[ ] documentation issue

Database system/driver:

[ ] cordova
[ ] mongodb
[ ] mssql
[x] mysql / mariadb
[ ] oracle
[ ] postgres
[ ] sqlite
[ ] sqljs
[ ] react-native
[ ] expo

TypeORM version:

[x] latest
[ ] @next
[ ] 0.x.x (or put your version here)

Steps to reproduce or a small repository showing the problem:

Some of my entities are mapped to temporary tables. Therefore, turning off synchronization for these entities is a must for me. With that, TypeORM won't attempt to create tables with the given name. However, if one of these entities contain a ManyToMany relation with a JoinTable, TypeORM always creates (unless syncronization is turned off globally) the junction table.
This also leads to database errors while TypeORM tries to create foreign key constraints between the junction table and the nonexistent temp tables.