SILGen: Fix assertion failure when accessing a property with a __consuming getter

We checked isMutating() on the accessor, and if it was false, called
isNonMutatingSelfIndirect(), which would assert that the accessor
satisfies isNonMutating().

However, isNonMutating() is not the opposite of isMutating(); rather,
one of isMutating(), isNonMutating() or isConsuming() is true.
Change the assertion to reflect this case.

Fixes rdar://problem/74095841.

Author: slavapestov

lib/SILGen/SILGenApply.cpp

@@ -4266,11 +4266,12 @@ bool SILGenModule::shouldEmitSelfAsRValue(FuncDecl *fn, CanType selfType) {
 
 bool SILGenModule::isNonMutatingSelfIndirect(SILDeclRef methodRef) {
   auto method = methodRef.getFuncDecl();
-  assert(method->getDeclContext()->isTypeContext());
-  assert(method->isNonMutating());
   if (method->isStatic())
     return false;
 
+  assert(method->getDeclContext()->isTypeContext());
+  assert(method->isNonMutating() || method->isConsuming());
+
   auto fnType = M.Types.getConstantFunctionType(TypeExpansionContext::minimal(),
                                                 methodRef);
   auto importAsMember = method->getImportAsMemberStatus();

test/SILGen/value_ownership.swift

@@ -57,3 +57,31 @@ struct Witness: OwnershipProto {
 
 // CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s15value_ownership7WitnessVAA14OwnershipProtoA2aDP17elidedPropertyGetSSvgTW :
 // CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s15value_ownership7WitnessVAA14OwnershipProtoA2aDP19explicitPropertyGetSSvgTW :
+
+// Check that references to a consuming getter are lowered properly.
+
+func blackHole<T>(_: T) {}
+
+// CHECK-LABEL: sil hidden [ossa] @$s15value_ownership25useConsumingGetterGenericyyxAA14OwnershipProtoRzlF : $@convention(thin) <T where T : OwnershipProto> (@in_guaranteed T) -> () {
+func useConsumingGetterGeneric<T : OwnershipProto>(_ t: T) {
+// CHECK:       [[FN:%.*]] = witness_method $T, #OwnershipProto.explicitPropertyGet!getter : <Self where Self : OwnershipProto> (__owned Self) -> () -> String : $@convention(witness_method: OwnershipProto) <τ_0_0 where τ_0_0 : OwnershipProto> (@in τ_0_0) -> @owned String
+// CHECK-NEXT:  apply [[FN]]<T>({{%.*}}) : $@convention(witness_method: OwnershipProto) <τ_0_0 where τ_0_0 : OwnershipProto> (@in τ_0_0) -> @owned String
+
+  blackHole(t.explicitPropertyGet)
+}
+
+// CHECK-LABEL: sil hidden [ossa] @$s15value_ownership29useConsumingGetterExistentialyyAA14OwnershipProto_pF : $@convention(thin) (@in_guaranteed OwnershipProto) -> () {
+func useConsumingGetterExistential(_ e: OwnershipProto) {
+// CHECK:      [[FN:%.*]] = witness_method $@opened("{{.*}}") OwnershipProto, #OwnershipProto.explicitPropertyGet!getter : <Self where Self : OwnershipProto> (__owned Self) -> () -> String, %2 : $*@opened("{{.*}}") OwnershipProto : $@convention(witness_method: OwnershipProto) <τ_0_0 where τ_0_0 : OwnershipProto> (@in τ_0_0) -> @owned String
+// CHECK-NEXT: apply [[FN]]<@opened("{{.*}}") OwnershipProto>({{%.*}}) : $@convention(witness_method: OwnershipProto) <τ_0_0 where τ_0_0 : OwnershipProto> (@in τ_0_0) -> @owned String
+
+  blackHole(e.explicitPropertyGet)
+}
+
+// CHECK-LABEL: sil hidden [ossa] @$s15value_ownership26useConsumingGetterConcreteyyAA7WitnessVF : $@convention(thin) (@guaranteed Witness) -> () {
+func useConsumingGetterConcrete(_ c: Witness) {
+// CHECK:      [[FN:%.*]] = function_ref @$s15value_ownership7WitnessV19explicitPropertyGetSSvg : $@convention(method) (@owned Witness) -> @owned String
+// CHECK-NEXT: apply [[FN]]({{%.*}}) : $@convention(method) (@owned Witness) -> @owned String
+
+  blackHole(c.explicitPropertyGet)
+}