Index: lib/Driver/ToolChains/Solaris.cpp
===================================================================
--- lib/Driver/ToolChains/Solaris.cpp
+++ lib/Driver/ToolChains/Solaris.cpp
@@ -71,6 +71,11 @@
       CmdArgs.push_back(
           Args.MakeArgString(getToolChain().GetFilePath("ld.so.1")));
     }
+
+    // libpthread has been folded into libc since Solaris 10, no need to do
+    // anything for pthreads. Claim argument to avoid warning.
+    Args.ClaimAllArgs(options::OPT_pthread);
+    Args.ClaimAllArgs(options::OPT_pthreads);
   }
 
   if (Output.isFilename()) {