Add helper


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5342 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Makefile.common b/Makefile.common
index 0d80d18..eb5b4b6 100644
--- a/Makefile.common
+++ b/Makefile.common
@@ -468,6 +468,10 @@
 	$(VERB) mkdir -p $(@D)
 	@date > $@
 
+# To create postscript files from dot files...
+%.ps: %.dot
+	dot -Tps < $< > $@
+
 # 'make clean' nukes the tree
 clean::
 	$(VERB) rm -rf $(BUILD_ROOT)/Debug $(BUILD_ROOT)/Release $(BUILD_ROOT)/Profile $(BUILD_ROOT)/Depend