Include error location when reporting imports that clash

[omelkonian]

The error produced when we detect clashing imports does not currently contain an error location, c.f. the clashingImports function.

One solution might be to add a field importRange :: Range to the type of Import records here and then tweak clashingImports like so:

     checkClashingImports :: Imports -> TCM ()
     checkClashingImports [] = return ()
-    checkClashingImports (Import mod as p q : is) =
+    checkClashingImports (Import mod as p q loc : is) =
       case filter isClashing is of
-        (i : _) -> genericDocError =<< text (mkErrorMsg i)
+        (i : _) -> setCurrentRange loc $ genericDocError =<< text (mkErrorMsg i)
         []      -> checkClashingImports is
      where
-        isClashing (Import _ as' p' q') = (as' == as) && (p' /= p) && (q' == q)
+        isClashing (Import _ as' p' q' _) = (as' == as) && (p' /= p) && (q' == q)
         mkErrorMsg (Import _ _ p' q') =
              "Clashing import: " ++ pp q ++ " (both from "
           ++ prettyShow (pp <$> p) ++ " and "

[jespercockx]

I tried to implement the fix suggested by @omelkonian in https://github.com/agda/agda2hs/tree/issue157. However, it's not working yet as the range of all the names in the internal syntax is seemingly set to noRange. Perhaps there's another place to get the information from, but I'm not sure.