Fix ghc-modi compat exe

src/GHCModi.hs

@@ -7,10 +7,13 @@ module Main where
 
 import System.Exit
 import System.Process
+import System.FilePath
 import System.Environment
+import Paths_ghc_mod
 
 main :: IO ()
 main = do
   args <- getArgs
-  h <- spawnProcess "ghc-mod" $ ["legacy-interactive"] ++ args
+  bindir <- getBinDir
+  h <- spawnProcess (bindir </> "ghc-mod") $ ["legacy-interactive"] ++ args
   exitWith =<< waitForProcess h