Index: lib/Driver/Types.cpp
===================================================================
--- lib/Driver/Types.cpp
+++ lib/Driver/Types.cpp
@@ -143,6 +143,7 @@
            .Case("S", TY_Asm)
            .Case("o", TY_Object)
            .Case("obj", TY_Object)
+           .Case("lib", TY_Object)
            .Case("ii", TY_PP_CXX)
            .Case("mi", TY_PP_ObjC)
            .Case("mm", TY_ObjCXX)