and undo_no_t. Each type is still defined as dulint.

This is an initial step towards replacing dulint with a 64-bit data type.
Because modern compilers have no trouble supporting 64-bit arithmetics
even on 32-bit targets, the dulint struct is a relic that should go.

The last remaining major use of dulint is dictionary IDs
(table, index, and row ids).

rb://114 approved by Sunny Bains