Revert "add regexp_benchmark target" This reverts commit d76eb213ec2644e7e0fde76278b64fb755eae921. This commits break re2 built with bazel and sandboxing and is based on an old unmaintained BUILD file for re2. Change-Id: I287db9a88334aac813bfe537c827214d16954417 Reviewed-on: https://code-review.googlesource.com/4440 Reviewed-by: Paul Wankadia <junyer@google.com>