Driver: Claim the -mlinker-version synthesized argument, it shouldn't be
reported as unused.

llvm-svn: 111310
diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 4b3bf32..5616300 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -166,6 +166,7 @@
   if (!Args.hasArg(options::OPT_mlinker_version_EQ)) {
     DAL->AddJoinedArg(0, Opts->getOption(options::OPT_mlinker_version_EQ),
                       HOST_LINK_VERSION);
+    DAL->getLastArg(options::OPT_mlinker_version_EQ)->claim();
   }
 #endif