Don't build dead directories


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8308 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/Makefile b/lib/CodeGen/Makefile
index f0a0431..224ac0c 100644
--- a/lib/CodeGen/Makefile
+++ b/lib/CodeGen/Makefile
@@ -1,5 +1,5 @@
 LEVEL = ../..
-PARALLEL_DIRS = PreOpts InstrSelection InstrSched RegAlloc PostOpts SelectionDAG
+PARALLEL_DIRS = InstrSelection InstrSched RegAlloc SelectionDAG
 LIBRARYNAME = codegen
 
 include $(LEVEL)/Makefile.common