gir1.2-javascriptcoregtk-4.1 2.39.91-1ubuntu1 (s390x binary) in ubuntu lunar

 JavaScriptCore is the JavaScript engine used in WebKit. It consists
 of the following building blocks: lexer, parser, start-up interpreter
 (LLInt), baseline JIT, a low-latency optimizing JIT (DFG), and a
 high-throughput optimizing JIT (FTL).
 .
 This build comes from the GTK port of WebKit (API version 4.1).
 .
 This package contains the introspection data, which can be used by
 packages using the GIRepository format to generate dynamic bindings.