do not use capi for dlfcn.h stuff under wasm-wasi

Author: redneb

System/Posix/DynamicLinker/Prim.hsc

@@ -85,10 +85,17 @@ data RTLDFlags
   | RTLD_LOCAL
     deriving (Show, Read)
 
+#if defined(HAVE_DLFCN_H)
 foreign import capi unsafe "dlfcn.h dlopen" c_dlopen :: CString -> CInt -> IO (Ptr ())
 foreign import capi unsafe "dlfcn.h dlsym"  c_dlsym  :: Ptr () -> CString -> IO (FunPtr a)
 foreign import capi unsafe "dlfcn.h dlerror" c_dlerror :: IO CString
 foreign import capi unsafe "dlfcn.h dlclose" c_dlclose :: (Ptr ()) -> IO CInt
+#else
+foreign import ccall unsafe "dlopen" c_dlopen :: CString -> CInt -> IO (Ptr ())
+foreign import ccall unsafe "dlsym"  c_dlsym  :: Ptr () -> CString -> IO (FunPtr a)
+foreign import ccall unsafe "dlerror" c_dlerror :: IO CString
+foreign import ccall unsafe "dlclose" c_dlclose :: (Ptr ()) -> IO CInt
+#endif // HAVE_DLFCN_H
 
 packRTLDFlags :: [RTLDFlags] -> CInt
 packRTLDFlags flags = foldl (\ s f -> (packRTLDFlag f) .|. s) 0 flags