Backwards compatible desugared library configuration.

Bug: 158645207
Change-Id: I6d298723aecd6693b3614527d9fd1dd3b524ed78
diff --git a/.gitignore b/.gitignore
index e184eb8..aa4c9ae 100644
--- a/.gitignore
+++ b/.gitignore
@@ -135,6 +135,8 @@
 third_party/protobuf-lite/
 third_party/r8
 third_party/r8.tar.gz
+third_party/r8-releases/2.0.74
+third_party/r8-releases/2.0.74.tar.gz
 third_party/r8mappings
 third_party/r8mappings.tar.gz
 third_party/remapper