Pass the right linker flag in openbsd::Link::ConstructJob,
patch by Matthew Dempsky!

llvm-svn: 126133
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 6717349..2f264e5 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -3085,7 +3085,7 @@
     CmdArgs.push_back("-lgcc");
 
     if (Args.hasArg(options::OPT_pthread))
-      CmdArgs.push_back("-pthread");
+      CmdArgs.push_back("-lpthread");
     if (!Args.hasArg(options::OPT_shared))
       CmdArgs.push_back("-lc");
     CmdArgs.push_back("-lgcc");