Fix a problem in the target detection for Debian GNU/HURD



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154117 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/configure b/configure
index 1e5e2c5..8ff4e62 100755
--- a/configure
+++ b/configure
@@ -3816,6 +3816,8 @@
     llvm_cv_target_os_type="Interix" ;;
   *-*-linux*)
     llvm_cv_target_os_type="Linux" ;;
+  *-*-gnu*)
+    llvm_cv_target_os_type="GNU" ;;
   *-*-solaris*)
     llvm_cv_target_os_type="SunOS" ;;
   *-*-auroraux*)