Revert "Remove hit_for_pass code in generic Wikimedia VCL"

This reverts commit 2becc88a85e3f516a0fb9731c50ef13c24f73166

This complements the revert for bef86cbb3d7efa13c95481148de2f6a561845f08.

Change-Id: Ia6c039e9491a617fd51ea8885dc0f26841fee347
Merge "Revert "Remove hit_for_pass code in generic Wikimedia VCL"" into production