paths.nim: Fix import for FreeBSD (#238)

Author: lbartoletti

src/nimib/paths.nim

@@ -1,4 +1,7 @@
-import "$nim/compiler/pathutils"
+when defined(FreeBSD):
+  import "$nim/lib/compiler/pathutils"
+else:
+  import "$nim/compiler/pathutils"
 export pathutils
 import os, strutils, hashes
 
@@ -53,4 +56,4 @@ template withDir*(dir: AbsoluteDir, body: untyped): untyped =
 proc getExt*(filename: string): string =
   let i = filename.searchExtPos
   if i > 0 and filename.len > i:
-    result = filename[(i+1) .. ^1]
+    result = filename[(i+1) .. ^1]