Add libfuzzer to buildtools gitignore

Change-Id: Ib54dc05a85b26ec0a3970316a6e7273fcb8873bd
diff --git a/buildtools/.gitignore b/buildtools/.gitignore
index 1dd47b9..f33608c 100644
--- a/buildtools/.gitignore
+++ b/buildtools/.gitignore
@@ -1,3 +1,4 @@
+android-core/
 android_sdk/
 aosp-*/
 benchmark/
@@ -10,15 +11,15 @@
 libbacktrace/
 libcxx/
 libcxxabi/
+libfuzzer/
 libunwind/
 linenoise/
 linux/
 linux64/
+lzma/
 mac/
 ndk/
 nodejs/
 protobuf/
 sqlite/
-android-core/
-lzma/
 test_data/