Add the AnyObject special case to the SIL parser's conformance logic.

Author: rjmccall

lib/Parse/ParseSIL.cpp

@@ -1429,6 +1429,12 @@ static bool allowAbstractConformance(Parser &P, Type subReplacement,
   if (!subReplacement->hasDependentProtocolConformances())
     return false;
 
+  // AnyObject is implicitly conformed to by anything with a class bound.
+  if (proto->isSpecificProtocol(KnownProtocolKind::AnyObject) &&
+      subReplacement->isAnyClassReferenceType()) {
+    return true;
+  }
+
   if (auto archetype = subReplacement->getAs<ArchetypeType>()) {
     return isImpliedBy(proto, archetype->getConformsTo());
   }

test/SIL/Parser/basic.sil

@@ -1419,7 +1419,6 @@ else:
   return %3void : $()
 } // CHECK: {{^}$}}
 
-
 // CHECK-LABEL: sil_vtable Foo {
 // CHECK: #Foo.subscript!getter.1: _TFC3tmp3Foog9subscriptFTVs5Int32S1__S1_
 // CHECK: #Foo.subscript!setter.1: _TFC3tmp3Foos9subscriptFTVs5Int32S1__S1_

test/SIL/Parser/basic_objc.sil

@@ -32,3 +32,11 @@ entry(%a : $@objc_metatype SomeClass.Type, %b : $@objc_metatype SomeClassProtoco
   return %z : $(AnyObject, AnyObject)
 }
 
+sil @requires_any_object : $@convention(thin) <T: AnyObject> (@owned T) -> ()
+
+sil @foo : $@convention(thin) (@owned ObjCProto) -> () {
+entry(%a : $ObjCProto):
+  %f = function_ref @requires_any_object : $@convention(thin) <T: AnyObject> (@owned T) -> ()
+  %0 = apply %f<ObjCProto>(%a) : $@convention(thin) <T: AnyObject> (@owned T) -> ()
+  return %0 : $()
+}