Add size to the property list.

It should now be possible to support newer ABIs.

class.h

@@ -244,7 +244,7 @@ struct legacy_gnustep_objc_class
 	* List of declared properties on this class (NULL if none).  This contains
 	* the accessor methods for each property.
 	*/
-	struct objc_property_list *properties;
+	struct objc_property_list_legacy *properties;
 
 	/**
 	 * GC / ARC ABI: Fields below this point only exist if abi_version is >= 1.

legacy.c

@@ -5,6 +5,7 @@
 #include "objc/runtime.h"
 #include "objc/encoding.h"
 #include "ivar.h"
+#include "properties.h"
 #include "class.h"
 #include "loader.h"
 
@@ -82,6 +83,20 @@ static struct objc_method_list *upgradeMethodList(struct objc_method_list_legacy
 	return l;
 }
 
+static struct objc_property_list *upgradePropertyList(struct objc_property_list_legacy *l)
+{
+	if (l == NULL)
+	{
+		return NULL;
+	}
+	size_t data_size = l->count * sizeof(struct objc_property);
+	struct objc_property_list *n = calloc(1, sizeof(struct objc_property_list) + data_size);
+	n->count = l->count;
+	n->size = sizeof(struct objc_property);
+	memcpy(n->properties, l->properties, data_size);
+	return n;
+}
+
 static int legacy_key;
 
 PRIVATE struct legacy_gnustep_objc_class* objc_legacy_class_for_class(Class cls)
@@ -102,7 +117,7 @@ PRIVATE Class objc_upgrade_class(struct legacy_gnustep_objc_class *oldClass)
 	cls->methods = upgradeMethodList(oldClass->methods);
 	cls->protocols = oldClass->protocols;
 	cls->abi_version = oldClass->abi_version;
-	cls->properties = oldClass->properties;
+	cls->properties = upgradePropertyList(oldClass->properties);
 	objc_register_selectors_from_class(cls);
 	if (!objc_test_class_flag(cls, objc_class_flag_meta))
 	{

properties.h

@@ -136,7 +136,7 @@ struct objc_property
 /**
  * List of property introspection data.
  */
-struct objc_property_list
+struct objc_property_list_legacy
 {
 	/**
 	 * Number of properties in this array.
@@ -152,6 +152,31 @@ struct objc_property_list
 	struct objc_property properties[];
 };
 
+/**
+ * List of property introspection data.
+ */
+struct objc_property_list
+{
+	/**
+	 * Number of properties in this array.
+	 */
+	int count;
+	/**
+	 * Size of `struct objc_property`.  This allows the runtime to
+	 * transparently support newer ABIs with more fields in the property
+	 * metadata.
+	 */
+	int size;
+	/*
+	 * The next property in a linked list.
+	 */
+	struct objc_property_list *next;
+	/**
+	 * List of properties.
+	 */
+	struct objc_property properties[];
+};
+
 /**
  * Constructs a property description from a list of attributes, returning the
  * instance variable name via the third parameter.

properties.m

@@ -671,6 +671,7 @@ BOOL class_addProperty(Class cls,
 	struct objc_property_list *l = calloc(1, sizeof(struct objc_property_list)
 			+ sizeof(struct objc_property));
 	l->count = 1;
+	l->size = sizeof(struct objc_property);
 	memcpy(&l->properties, &p, sizeof(struct objc_property));
 	LOCK_RUNTIME_FOR_SCOPE();
 	l->next = cls->properties;