Vulkan: Attachment LoadOp and StoreOp are not handled correctly in DCE

[Qining]

According to spec:
loadOp is a VkAttachmentLoadOp value specifying how the contents of color and depth components of the attachment are treated at the beginning of the subpass where it is first used.

storeOp is a VkAttachmentStoreOp value specifying how the contents of color and depth components of the attachment are treated at the end of the subpass where it is last used.

Instead, the current DCE refer to the LoadOp and StoreOp for each subpass, which is not right. This makes the replay result of some multi-subpass samples wrong.