Add 'make cscope.files' top level target.

llvm-svn: 67168
diff --git a/clang/Makefile b/clang/Makefile
index 660f0e9..b4f60a8 100644
--- a/clang/Makefile
+++ b/clang/Makefile
@@ -23,4 +23,10 @@
 tags::
 	$(Verb) etags `find . -type f -name \*.h | grep -v /lib/Headers | grep -v /test/` `find . -type f -name \*.cpp | grep -v /lib/Headers | grep -v /test/`
 
-.PHONY: test report clean
+cscope.files:
+	find Driver lib include -name '*.cpp' \
+	                    -or -name '*.def' \
+	                    -or -name '*.td' \
+	                    -or -name '*.h' > cscope.files
+
+.PHONY: test report clean cscope.files