.gitignore file needed for new replication parser

diff --git a/src/backend/replication/.gitignore
b/src/backend/replication/.gitignore
new file mode 100644
index 0000000..a0332b2
--- /dev/null
+++ b/src/backend/replication/.gitignore
@@ -0,0 +1,3 @@
+/repl_gram.c
+/repl_gram.h
+/repl_scanner.c