(|a)* shouldn't match more text than (|a)+ does!

Fixes #310.

Change-Id: I16c500e4b4c67a9f01dc9403773f3a40356ecc4d
Reviewed-on: https://code-review.googlesource.com/c/re2/+/58590
Reviewed-by: Paul Wankadia <junyer@google.com>
4 files changed