* Makefile.in: Add support for foreign threads on VMS.

From-SVN: r91889

gcc/ada/Makefile.in

@@ -1241,7 +1241,7 @@ endif
   s-osprim.ads<s-osprim-vms.ads \
   s-taprop.adb<s-taprop-vms.adb \
   s-taspri.ads<s-taspri-vms.ads \
-  s-tpopsp.adb<s-tpopsp-posix.adb \
+  s-tpopsp.adb<s-tpopsp-posix-foreign.adb \
   s-tpopde.adb<s-tpopde-vms.adb \
   s-tpopde.ads<s-tpopde-vms.ads \
   s-traent.adb<s-traent-vms.adb \