Add a hacky way to get local executable path

cry

@@ -19,6 +19,7 @@ Available commands:
   build     Build Cryptol
   haddock   Generate Haddock documentation
   test      Run some tests
+  exe-path  Print the location of the local executable
 EOM
 }
 
@@ -78,6 +79,10 @@ case $COMMAND in
     show_usage
     exit 0;;
 
+  exe-path)
+    cabal v2-run exe:cryptol --verbose -- -c ':q' | grep :q | awk '{ print $1 }'
+    exit 0;;
+
   *)
     echo Unrecognized command: $COMMAND
     show_usage