versioner: add support for preprocessing headers.

Bug: http://b/30170081
Change-Id: I9b662ca9e0fa3a1f9c0211594e851f5f9bef7266
diff --git a/tools/versioner/tests/preprocessor_merging/run.sh b/tools/versioner/tests/preprocessor_merging/run.sh
new file mode 100644
index 0000000..1b0aae2
--- /dev/null
+++ b/tools/versioner/tests/preprocessor_merging/run.sh
@@ -0,0 +1,4 @@
+rm -rf out
+set -e
+versioner headers -i -o out
+diff -q -w -B out expected