Retain and autorelease associated objects properly (#331)

Apple's objc4 runtime expands the policy bits into the following
subcategories:

```
enum {
    OBJC_ASSOCIATION_SETTER_ASSIGN      = 0,
    OBJC_ASSOCIATION_SETTER_RETAIN      = 1,
    OBJC_ASSOCIATION_SETTER_COPY        = 3,
    OBJC_ASSOCIATION_GETTER_READ        = (0 << 8),
    OBJC_ASSOCIATION_GETTER_RETAIN      = (1 << 8),
    OBJC_ASSOCIATION_GETTER_AUTORELEASE = (2 << 8)
};
```

where

OBJC_ASSOCIATION_ASSIGN = 0
OBJC_ASSOCIATION_RETAIN_NONATOMIC = 1
OBJC_ASSOCIATION_COPY_NONATOMIC = 3
OBJC_ASSOCIATION_RETAIN = 01401
OBJC_ASSOCIATION_COPY = 01403

This means that on OBJC_ASSOCIATION_{RETAIN, COPY} and the
NONATOMIC counterpart, we need to retain and autorelease the associated
object before returning it in objc_getAssociatedObject.


* Cirrus: Bump freebsd image versions

Author: hmelder

.cirrus.yml

@@ -1,11 +1,11 @@
 libcxxrt_freebsd_task:
   matrix:
   - freebsd_instance:
-     image_family: freebsd-13-3
+     image_family: freebsd-13-5
   - freebsd_instance:
      image_family: freebsd-15-0-snap
   - freebsd_instance:
-     image_family: freebsd-14-0
+     image_family: freebsd-14-2
 
   install_script: pkg install -y cmake ninja git
 
@@ -31,7 +31,7 @@ libcxxrt_freebsd_task:
 
 libcxxrt_master_task:
   freebsd_instance:
-    image_family: freebsd-14-0
+    image_family: freebsd-14-2
   install_script: pkg install -y cmake ninja git
 
   clone_script: |

Test/AssociatedObject.m

@@ -41,9 +41,11 @@ int main(void)
 
 	object = [Associated new];
 	holder = [Test new];
+	size_t rc = object_getRetainCount_np(object);
 	for (uintptr_t i = 1; i <= 20; ++i)
 	{
 		objc_setAssociatedObject(holder, (void*)i, object, OBJC_ASSOCIATION_RETAIN);
+		assert(rc + i == object_getRetainCount_np(object));
 	}
 	int lost = 0;
 	for (uintptr_t i = 1; i <= 20; ++i)
@@ -53,6 +55,7 @@ int main(void)
 			fprintf(stderr, "lost object %" PRIuPTR "\n", i);
 			++lost;
 		}
+		assert(rc + 20 + i == object_getRetainCount_np(object));
 	}
 	[holder release];
 	[object release];

associate.m

@@ -341,6 +341,12 @@ id objc_getAssociatedObject(id object, const void *key)
 	struct reference *r = findReference(list, key);
 	if (NULL != r)
 	{
+		// Check if the policy is OBJC_ASSOCIATION_{RETAIN, COPY} or OBJC_ASSOCIATION_{RETAIN, COPY}_NONATOMIC (LSB set)
+		// Apple's objc4 retains and autoreleases the object under these policies
+		if (r->policy & OBJC_ASSOCIATION_RETAIN_NONATOMIC)
+		{
+			objc_retainAutorelease(r->object);
+		}
 		return r->object;
 	}
 	if (class_isMetaClass(object->isa))
@@ -364,6 +370,10 @@ id objc_getAssociatedObject(id object, const void *key)
 				struct reference *r = findReference(list, key);
 				if (NULL != r)
 				{
+					if (r->policy & OBJC_ASSOCIATION_RETAIN_NONATOMIC)
+					{
+						objc_retainAutorelease(r->object);
+					}
 					return r->object;
 				}
 			}