Fix some coercions

Author: garyb

src/Web/DOM/Comment.purs

@@ -12,7 +12,7 @@ import Web.Internal.FFI (unsafeReadProtoTagged)
 foreign import data Comment :: Type
 
 fromCharacterData :: CharacterData -> Maybe Comment
-fromCharacterData = unsafeCoerce
+fromCharacterData = unsafeReadProtoTagged "Comment"
 
 fromNode :: Node -> Maybe Comment
 fromNode = unsafeReadProtoTagged "Comment"
@@ -26,7 +26,7 @@ fromNonDocumentTypeChildNode = unsafeReadProtoTagged "Comment"
 fromEventTarget :: EventTarget -> Maybe Comment
 fromEventTarget = unsafeReadProtoTagged "Comment"
 
-toCharacterData :: Comment -> Comment
+toCharacterData :: Comment -> CharacterData
 toCharacterData = unsafeCoerce
 
 toNode :: Comment -> Node
@@ -38,5 +38,5 @@ toChildNode = unsafeCoerce
 toNonDocumentTypeChildNode :: Comment -> NonDocumentTypeChildNode
 toNonDocumentTypeChildNode = unsafeCoerce
 
-toEventTarget :: Node -> Comment
+toEventTarget :: Comment -> EventTarget
 toEventTarget = unsafeCoerce

src/Web/DOM/DocumentFragment.purs

@@ -29,7 +29,7 @@ fromEventTarget = unsafeReadProtoTagged "DocumentFragment"
 toNode :: DocumentFragment -> Node
 toNode = unsafeCoerce
 
-toChildNode :: DocumentFragment -> Node
+toChildNode :: DocumentFragment -> ChildNode
 toChildNode = unsafeCoerce
 
 toParentNode :: DocumentFragment -> ParentNode

src/Web/DOM/ProcessingInstruction.purs

@@ -39,7 +39,7 @@ toChildNode = unsafeCoerce
 toNonDocumentTypeChildNode :: ProcessingInstruction -> NonDocumentTypeChildNode
 toNonDocumentTypeChildNode = unsafeCoerce
 
-toEventTarget :: Node -> ProcessingInstruction
+toEventTarget :: ProcessingInstruction -> EventTarget
 toEventTarget = unsafeCoerce
 
 foreign import target :: ProcessingInstruction -> Effect String

src/Web/DOM/Text.purs

@@ -39,7 +39,7 @@ toChildNode = unsafeCoerce
 toNonDocumentTypeChildNode :: Text -> NonDocumentTypeChildNode
 toNonDocumentTypeChildNode = unsafeCoerce
 
-toEventTarget :: Node -> Text
+toEventTarget :: Text -> EventTarget
 toEventTarget = unsafeCoerce
 
 foreign import splitText :: Int -> Text -> Effect Text