Debugger updates

Support for inspecting more types of instances in the
variables viewer (Expandos, Types, TypeArguments,
Parameters, Closures + closure Contexts,
WeakProperty, Function, FunctionType, ReceivePort,
Closure, RegExp) -
#4760

Add support for displaying coverage in CodeView -
#4700

Network updates

Display request data if content type is not json
(thanks to leungpuikuen@!) -
#4602

Changelog

More details about changes and fixes are available in the DevTools
changelog.