Add a WORKSPACE.bzlmod file.

https://bazel.build/external/migration#workspace.bzlmod describes what
it does. https://bazel.build/external/migration#builtin-default-deps
is what's particularly interesting: we want to be assured that builds
will continue to work without Bazel adding "prefixes and suffixes".

Credit to Yun Peng for suggesting this.

Change-Id: I138676909a594eab1872647c4398f953e0a6eda3
Reviewed-on: https://code-review.googlesource.com/c/re2/+/61671
Reviewed-by: Alex Chernyakhovsky <[email protected]>
Reviewed-by: Paul Wankadia <[email protected]>

Author: junyer

WORKSPACE.bzlmod

@@ -0,0 +1,7 @@
+# Copyright 2009 The RE2 Authors.  All Rights Reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+# Bazel (http://bazel.build/) WORKSPACE file for RE2.
+
+workspace(name = "com_googlesource_code_re2")