Fix #580: Catch exceptions that escape JS test framework in test bridge
Merge pull request #583 from gzm0/failsafe-test-bridge

Fix #580: Catch exceptions that escape JS test framework in test bridge
Fix #575: Add Scala.js magic number and version to IR binary format
Merge pull request #584 from gzm0/ir-version

Fix #575: Add Scala.js magic number and version to IR binary format