Pass "-z relro" as two arguments. This works with both gnu ld and gold.
Patch by Frits van Bommel.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@118406 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/ToolChains.cpp b/lib/Driver/ToolChains.cpp
index 57743e5..6a15666 100644
--- a/lib/Driver/ToolChains.cpp
+++ b/lib/Driver/ToolChains.cpp
@@ -1360,8 +1360,10 @@
 
   LinuxDistro Distro = DetectLinuxDistro(Arch);
 
-  if (IsUbuntu(Distro))
-    ExtraOpts.push_back("-z relro");
+  if (IsUbuntu(Distro)) {
+    ExtraOpts.push_back("-z");
+    ExtraOpts.push_back("relro");
+  }
 
   if (Arch == llvm::Triple::arm)
     ExtraOpts.push_back("-X");