Most clients don't have a notion of "address" and pass arbitrary values
(including `0` and `sizeof(void *)`) to `DataExtractor` constructors.
This makes address-extraction methods dangerous to use.
Those clients that do have a notion of address can use other methods
like `getUnsigned()` to extract an address, or they can derive from
`DataExtractor` and add convenience methods if extracting an address is
routine. `DWARFDataExtractor` is an example, where the removed methods
were actually moved.
This does not remove `AddressSize` argument of `DataExtractor`
constructors yet, but makes it unused and overloads constructors in
preparation for their deletion. I'll be removing uses of the
to-be-deleted constructors in follow-up patches.
b6ff43f1ec