Previously we were linking in all SIL entities
if the input was a serialized non-SIB AST, and
`-disable-sil-linking` wasn't specified. However
none of the tests appear to want this behaviour.
Stop calling `SerializedSILLoader::getAll`, and
remove the `-disable-sil-linking` option, as this
is now the default behaviour.
...fulfilling the promised audit from 0747d9a339. No intended
functionality change /other/ than the order of already-unsorted lists.
This affected a number of SIL tests that relied on deserialization
order matching the original source order; I have no idea why the old
hash logic would make that the case. If we think that's a valuable
property, we should serialize a list of functions in addition to the
iterable table. (Maybe just in SIB mode?)
