Oops - this should have been part of r116159, but I forgot to include it on the…

Oops - this should have been part of r116159, but I forgot to include it on the commit command line. Doh!

From-SVN: r116180

gcc/config.gcc

@@ -1275,7 +1275,10 @@ i[34567]86-*-mingw32*)
 	extra_objs="winnt.o winnt-stubs.o"
 	cxx_target_objs=winnt-cxx.o
 	case ${enable_threads} in
-	  "" | yes | win32) thread_file='win32' ;;
+	  "" | yes | win32)
+	  thread_file='win32'
+	  tmake_file="${tmake_file} i386/t-gthr-win32"
+	  ;;
 	esac
 	case ${target} in
 		*mingw32crt*)