hsc2hs parses incorrectly c99 style ("/// ...") comments in '--cross-compile' mode

The code is simplified version of something from Win32 package (https://github.com/haskell/win32/blob/master/Graphics/Win32/GDI/Pen.hsc#L59):

-- a.hsc
#{enum Int ,     // "hi" there!
 , a       = sizeof(int)
 }

$ hsc2hs a.hsc -o a.hs-cross --cross-compile
$ hsc2hs a.hsc -o a.hs-native

--- a.hs-cross  2017-04-26 21:56:56.157323964 +0100
+++ a.hs-native 2017-04-26 21:57:00.753311717 +0100
@@ -2,3 +2,3 @@
 a        :: Int
-a        = // "hi" there! 4
+a        =  4

I'm not sure if it's a valid .hsc but having at least the same (valid or invalid) result in both modes would be nice.

Trac metadata

Trac field	Value
Version	8.0.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	hsc2hs
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	Phyx-, hvr
Operating system
Architecture