Fix small memory leak during swapchain creation.

Add ability to profile Cube demo on macOS.

Demos/Cube/Cube.xcodeproj/xcshareddata/xcschemes/Cube-macOS.xcscheme

@@ -62,7 +62,8 @@
       savedToolIdentifier = ""
       useCustomWorkingDirectory = "NO"
       debugDocumentVersioning = "YES">
-      <MacroExpansion>
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
          <BuildableReference
             BuildableIdentifier = "primary"
             BlueprintIdentifier = "A9B53B0F1C3AC0BE00ABC6F6"
@@ -70,7 +71,7 @@
             BlueprintName = "Cube-macOS"
             ReferencedContainer = "container:Cube.xcodeproj">
          </BuildableReference>
-      </MacroExpansion>
+      </BuildableProductRunnable>
    </ProfileAction>
    <AnalyzeAction
       buildConfiguration = "Debug">

Docs/Whats_New.md

@@ -36,6 +36,7 @@ Released TBD
 - On command buffer submission failure, if `MVKConfiguration::resumeLostDevice` enabled,  do not release 
   waits on `VkDevice`, and do not return `VK_ERROR_DEVICE_LOST`, unless `VkPhysicalDevice` is also lost.
 - Fix inconsistent handling of linear attachment decisions on Apple Silicon.
+- Fix small memory leak during swapchain creation.
 - Protect against crash when retrieving `MTLTexture` when `VkImage` has no `VkDeviceMemory` bound.
 - Adjust some `VkPhysicalDeviceLimits` values for Vulkan and Metal compliance. 
 - Fix internal reference from `SPIRV_CROSS_NAMESPACE_OVERRIDE` to `SPIRV_CROSS_NAMESPACE`.

MoltenVK/MoltenVK/Utility/MVKBlockObserver.m

@@ -47,6 +47,7 @@
 
 - (void)dealloc {
 	[self stopObserving];
+	[_block release];
 	[super dealloc];
 }