swift234

Revert "Eliminate race in swift_bridgeErrorToNSError."

This reverts commit e07e88706d873c34d5d939ac0126be65e3078f1c. The
crash came back, so there's obviously more I need to investigate here:

  https://ci.swift.org/job/swift-PR-osx-smoke-test/881/testReport/junit/Swift(macosx-x86_64)/stdlib/ErrorProtocol_swift/