Use PhutilAggregateException to aggregate unit test exceptions
Use PhutilAggregateException to aggregate unit test exceptions

Summary: Currently, a shutdown exception ("script exited with open transactions!") overwhelms the actual test failure exception, which is the one that needs to be fixed.

Test Plan: Ran a fixture test which opens a transaction and then throws. Got diagnostically useful output after this patch.

Reviewers: vrana, btrahan

Reviewed By: vrana

CC: aran

Differential Revision: https://secure.phabricator.com/D3780

calblueprint/arcanist,chundongwang/arcanist,wxstars/arcanist,coursera/arcanist,dguo-coursera/arcanist,jra3/arcanist,eSpark/arcanist,Khan/arcanist,kevinseelbach/arcanist,aik099/arcanist,r4nt/arcanist,calblueprint/arcanist,zhihu/arcanist,coursera/arcanist,jra3/arcanist,Khan/arcanist,PageUpPeopleOrg/arcanist-patches,coursera/arcanist,Symplicity/arcanist,haskell-infra/arcanist,phacility/arcanist,coursera/arcanist,dguo-coursera/arcanist,folsom-labs/arcanist,haskell-infra/arcanist,uber/arcanist,uber/arcanist,haskell-infra/arcanist,hach-que/arcanist,KieranHayes/arcanist,chundongwang/arcanist,dguo-coursera/arcanist,folsom-labs/arcanist,hach-que/arcanist,alexmv/arcanist,memsql/arcanist,julkiewicz/arcanist,KieranHayes/arcanist,memsql/arcanist,PageUpPeopleOrg/arcanist-patches,phacility/arcanist,uber/arcanist,julkiewicz/arcanist,fivestars/arcanist,kevinseelbach/arcanist,eSpark/arcanist,codelabs-ch/arcanist,kevinseelbach/arcanist,Symplicity/arcanist,Symplicity/arcanist,wxstars/arcanist,zhihu/arcanist,KieranHayes/arcanist,uber/arcanist,Symplicity/arcanist,fivestars/arcanist,wharris/arcanist,Khan/arcanist,codelabs-ch/arcanist,alexmv/arcanist,eSpark/arcanist,dguo-coursera/arcanist,folsom-labs/arcanist,jra3/arcanist,wharris/arcanist,kevinseelbach/arcanist,codelabs-ch/arcanist,r4nt/arcanist,julkiewicz/arcanist,wharris/arcanist,zhihu/arcanist,r4nt/arcanist,KieranHayes/arcanist,fivestars/arcanist,sneakpeeq/arcanist,calblueprint/arcanist,PageUpPeopleOrg/arcanist-patches,jra3/arcanist,phacility/arcanist,alexmv/arcanist,zhihu/arcanist,wikimedia/phabricator-arcanist,haskell-infra/arcanist,Khan/arcanist,PageUpPeopleOrg/arcanist-patches,aik099/arcanist,memsql/arcanist,sneakpeeq/arcanist,codelabs-ch/arcanist,wikimedia/phabricator-arcanist,fivestars/arcanist,chundongwang/arcanist,wikimedia/phabricator-arcanist,eSpark/arcanist,sneakpeeq/arcanist,wharris/arcanist,memsql/arcanist,codelabs-ch/arcanist,hach-que/arcanist,r4nt/arcanist,phacility/arcanist,folsom-labs/arcanist,hach-que/arcanist,wxstars/arcanist,wxstars/arcanist,aik099/arcanist,sneakpeeq/arcanist,wikimedia/phabricator-arcanist,alexmv/arcanist,calblueprint/arcanist,aik099/arcanist,julkiewicz/arcanist,phacility/arcanist,chundongwang/arcanist