Remove castFunPtrToLONG

It's not used in a GHC tree, and doesn't really make sense on Win64

Author: igfoo

System/Win32/Types.hs

@@ -275,9 +275,6 @@ foreign import ccall unsafe "HsWin32.h"
 foreign import ccall unsafe "HsWin32.h"
   castPtrToUINTPtr :: Ptr s -> UINT_PTR
 
-foreign import ccall unsafe "HsWin32.h"
-  castFunPtrToLONG :: FunPtr a -> LONG
-
 type LCID = DWORD
 
 type LANGID = WORD

include/HsWin32.h

@@ -14,7 +14,6 @@
 
 INLINE UINT_PTR castPtrToUINTPtr(void *p) { return (UINT_PTR)p; }
 INLINE void *castUINTPtrToPtr(UINT_PTR n) { return (void *)n; }
-INLINE LONG castFunPtrToLONG(void *p) { return (LONG)p; }
 INLINE WORD hIWORD(DWORD w) { return HIWORD(w); }
 INLINE WORD lOWORD(DWORD w) { return LOWORD(w); }