Ignore the generate_library_loader directory

Review-Url: https://codereview.chromium.org/1952853002
diff --git a/.gitignore b/.gitignore
index 2ecaf97..df5f017 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,6 +9,7 @@
 /third_party/llvm-build
 /third_party/skia
 /tools/clang
+/tools/generate_library_loader
 /tools/gyp
 /v8
 /xcodebuild