Move gerrit-index/antlr3 sources to top-level antlr3 directory

Change-Id: I75d6bc4d7af2cb17622ef0f722f88f068509cb46
diff --git a/lib/antlr/BUILD b/lib/antlr/BUILD
index 37a354e..3642b90 100644
--- a/lib/antlr/BUILD
+++ b/lib/antlr/BUILD
@@ -22,7 +22,7 @@
     name = "antlr-tool",
     jvm_flags = ["-XX:-UsePerfData"],
     main_class = "org.antlr.Tool",
-    visibility = ["//gerrit-index:__pkg__"],
+    visibility = ["//antlr3:__pkg__"],
     runtime_deps = [":tool"],
 )