List most common failures on the daily report.

Change-Id: Ia07f73601727f71e5f2abee7c40886e2a05209bb
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/27472Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Ben Clayton <bclayton@google.com>