serialization unique id is broken without persistent lifetime

[borisbat]

Damage report

can't use intptr_t(object_ptr*) - produces clashes, when programs are compiled\deleted in the middle of serialization loop

Proposed fix

• use gc_node::gc_id where possible
• use custom das_hash_map<weak_id, strong_id> for everything else. weak_id is void * of original object, strong id is monotone counter within the serializer

Tests required

• resurrect -ser -deser tests on the CI
• undo Boris's changes to dastest etc - to use common serializer for all programs. try with /tests, if too slow narrow down to /tests/language

[aleksisch]

Was fixed in:
#2460