The ExistentialSpecializer incorrectly assumed that an existential's conformances match an opened archetype. They don't. Opened archetypes strip inherited conformances per the ABI for generic argument passing. Existential values retain those inherited conformances (for some inexplicable reason).
- Rename ASTContext::getExistentialSignature() to
getOpenedArchetypeSiganture() because it was doing exactly the wrong
thing for existentials.
- Fix ConcreteExistentialInfo to produce the correct SubstitutionMap.
- Fix ExistentialSpecializer to generate the correct conformances for
init_existential by adding a collectExistentialConformances() helper.
Fixes <rdar://problem/57025861> "Assertion failed: (conformances.size() == numConformanceRequirements)" in ExistentialSpecializer on inlined code
This option no longer works but was still in the option file and help
message.
Add a temporary pass-specific option instead for debugging until this
pass has been sufficiently tested yet.
