go/packages: update comment on when golist fallback triggers

It triggers for all go versions before 1.11. We thought we might
be able to backport some of the necessary changes to 1.10.4, but
it was infeasible, so no 1.10.x versions will support the non-fallback
behavior.

Change-Id: Ib22be2715bf504464e4bd09c14453e5d132776f3
Reviewed-on: https://go-review.googlesource.com/c/156898
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/go/packages/golist_fallback.go b/go/packages/golist_fallback.go
index 8e88607..ca08cf7 100644
--- a/go/packages/golist_fallback.go
+++ b/go/packages/golist_fallback.go
@@ -21,7 +21,7 @@
 // TODO(matloob): Delete this file once Go 1.12 is released.
 
 // This file provides backwards compatibility support for
-// loading for versions of Go earlier than 1.10.4. This support is meant to
+// loading for versions of Go earlier than 1.11. This support is meant to
 // assist with migration to the Package API until there's
 // widespread adoption of these newer Go versions.
 // This support will be removed once Go 1.12 is released