Add support for the OpenBSD for Bitrig.

Patch by David Hill.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161344 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/Unix/Path.inc b/lib/Support/Unix/Path.inc
index b41390a..6bddbdf 100644
--- a/lib/Support/Unix/Path.inc
+++ b/lib/Support/Unix/Path.inc
@@ -260,7 +260,7 @@
   return Path(pathname);
 }
 
-#if defined(__FreeBSD__) || defined (__NetBSD__) || \
+#if defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \
     defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__)
 static int
 test_dir(char buf[PATH_MAX], char ret[PATH_MAX],
@@ -329,7 +329,7 @@
     if (realpath(exe_path, link_path))
       return Path(link_path);
   }
-#elif defined(__FreeBSD__) || defined (__NetBSD__) || \
+#elif defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \
       defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__)
   char exe_path[PATH_MAX];