Remove the 'R' modifier.

It is not present in GNU or OS X versions and doesn't make a lot of sense
for llvm-ar.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184306 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Archive/directory.ll b/test/Archive/directory.ll
new file mode 100644
index 0000000..f17ac5d
--- /dev/null
+++ b/test/Archive/directory.ll
@@ -0,0 +1,2 @@
+;RUN: not llvm-ar r %T/test.a . 2>&1 | FileCheck %s
+;CHECK: . Is a directory