IRGen: Lookup the conformance of an archetype in the right substitution map when computing necessary bindings of abstract cnditional requirements

SR-12853

Author: aschwaighofer

lib/IRGen/GenProto.cpp

@@ -2749,9 +2749,12 @@ static void addAbstractConditionalRequirements(
     auto *proto =
         req.getSecondType()->castTo<ProtocolType>()->getDecl();
     auto ty = req.getFirstType()->getCanonicalType();
-    if (!isa<ArchetypeType>(ty))
+    auto archetype =  dyn_cast<ArchetypeType>(ty);
+    if (!archetype)
       continue;
-    auto conformance = subMap.lookupConformance(ty, proto);
+    auto *genericEnv = archetype->getGenericEnvironment();
+    auto conformance =
+        genericEnv->getForwardingSubstitutionMap().lookupConformance(ty, proto);
     if (!conformance.isAbstract())
       continue;
     requirements.insert({ty, conformance.getAbstract()});

test/IRGen/partial_apply_forwarder.sil

@@ -291,7 +291,7 @@ bb0(%0 : $Outer<Inner<Element>>):
   return %15 : $()
 }
 
-sil @$dont_crash_test_capture_specialized_conditional_conformance_nested : $@convention(thin) <Element where Element : MyEquatable> (Outer<Inner<Element>>) -> () {
+sil @$dont_crash_test_capture_specialized_conditional_conformance_nested : $@convention(thin) <A, B, Element where Element : MyEquatable> (Outer<Inner<Element>>) -> () {
 bb0(%0 : $Outer<Inner<Element>>):
   %4 = metatype $@thin Outermost<Outer<Inner<Element>>>.Type
   %5 = function_ref @$closure2 : $@convention(method) <Value where Value : MyEquatable> (Outermost<Value>, Outermost<Value>, @thin Outermost<Value>.Type) -> Builtin.Int1