Datapoint East Anglian English/Relativizer that or what in non-restrictive contexts

Variety: East Anglian English
Feature: Relativizer that or what in non-restrictive contexts
Value: A - feature is pervasive or obligatory
Informants: Peter Trudgill

Examples

Example 398:
That's the one what I give him last night
Example 399:
My daughter, what live up London,…