gitignore tagfile test.dat.
diff --git a/org.eclipse.jdt.core.tests.compiler/.gitignore b/org.eclipse.jdt.core.tests.compiler/.gitignore
new file mode 100644
index 0000000..650e459
--- /dev/null
+++ b/org.eclipse.jdt.core.tests.compiler/.gitignore
@@ -0,0 +1 @@
+/test.dat