Major Description
When do master unsafe_rebuild, tables' next_column_id is set to (2^31 - 1) / 2, i.e. 2^30 - 1.
After that, new added column's id is set to 2^30 - 1, 2^30, 2^30 + 1, ... We use an IdMapping to maintainance column id to it's index, like 2^30 - 1 -> 200, 2^30 -> 201, 2^30 + 1 -> 202.
However, the IdMapping's implemention use a vector to save all the k-v pairs, and the key is nearly the index of IdMapping. So we have to use a very large vector to save a column id like 2^30, and future more, it will increase doubly when found capacity not enough.
When the column id is 2^30, the double size is 2^31, which is overflow, will cause master crash.