Skip ivars that aren't available

This fixes a crash in CodeGen.

rdar://137999979

Author: ahatanaka

clang/lib/CodeGen/CGObjCMac.cpp

@@ -5308,6 +5308,9 @@ void IvarLayoutBuilder::visitAggregate(Iterator begin, Iterator end,
   for (; begin != end; ++begin) {
     auto field = *begin;
 
+    if (CGM.getContext().hasUnavailableFeature(field))
+      continue;
+
     // Skip over bitfields.
     if (field->isBitField()) {
       continue;

clang/lib/CodeGen/CodeGenModule.cpp

@@ -6759,9 +6759,12 @@ void CodeGenModule::EmitObjCPropertyImplementations(const
 static bool needsDestructMethod(ObjCImplementationDecl *impl) {
   const ObjCInterfaceDecl *iface = impl->getClassInterface();
   for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
-       ivar; ivar = ivar->getNextIvar())
+       ivar; ivar = ivar->getNextIvar()) {
+    if (impl->getASTContext().hasUnavailableFeature(ivar))
+      continue;
     if (ivar->getType().isDestructedType())
       return true;
+  }
 
   return false;
 }

clang/test/CodeGenObjC/feature-availability.m

@@ -69,7 +69,7 @@
 // CHECK-NEXT: @"_OBJC_$_PROP_LIST_C2" = internal global { i32, i32, [3 x %struct._prop_t] } { i32 16, i32 3, [3 x %struct._prop_t] [%struct._prop_t { ptr @OBJC_PROP_NAME_ATTR_.24, ptr @OBJC_PROP_NAME_ATTR_.25 }, %struct._prop_t { ptr @OBJC_PROP_NAME_ATTR_.26, ptr @OBJC_PROP_NAME_ATTR_.27 }, %struct._prop_t { ptr @OBJC_PROP_NAME_ATTR_.28, ptr @OBJC_PROP_NAME_ATTR_.29 }] }, section "__DATA, __objc_const", align 8
 // CHECK-NEXT: @"_OBJC_CLASS_RO_$_C2" = internal global %struct._class_ro_t { i32 0, i32 8, i32 32, ptr null, ptr @OBJC_CLASS_NAME_.11, ptr @"_OBJC_$_INSTANCE_METHODS_C2", ptr null, ptr @"_OBJC_$_INSTANCE_VARIABLES_C2", ptr null, ptr @"_OBJC_$_PROP_LIST_C2" }, section "__DATA, __objc_const", align 8
 // CHECK-NEXT: @"OBJC_CLASS_$_C2" = global %struct._class_t { ptr @"OBJC_METACLASS_$_C2", ptr @"OBJC_CLASS_$_NSObject", ptr @_objc_empty_cache, ptr @_objc_empty_vtable, ptr @"_OBJC_CLASS_RO_$_C2" }, section "__DATA, __objc_data", align 8
-// CHECK-NEXT: @"OBJC_LABEL_CLASS_$" = private global [2 x ptr] [ptr @"OBJC_CLASS_$_C0", ptr @"OBJC_CLASS_$_C2"], section "__DATA,__objc_classlist,regular,no_dead_strip", align 8
+// CHECK: @"OBJC_LABEL_CLASS_$" = private global [3 x ptr] [ptr @"OBJC_CLASS_$_C0", ptr @"OBJC_CLASS_$_C2", ptr @"OBJC_CLASS_$_C3"], section "__DATA,__objc_classlist,regular,no_dead_strip", align 8
 
 @interface NSObject {
   id a;
@@ -172,3 +172,10 @@ @interface C2 : NSObject
 
 @implementation C2
 @end
+
+@interface C3 : NSObject
+@property id prop0 __attribute__((availability(domain:feature2, AVAIL)));
+@end
+
+@implementation C3
+@end