Our generated code does not keep the context in a special register
anymore (for quite some time now). The context is just another definition
in the IR language and gets assigned register locations by the linearscan
register allocator.
Furthermore we no longer use an empty context for closures which have no
captured states, instead the context of those closures is just `null`.
This CL therefore removes Object::empty_context() and the CTX constant.
Change-Id: Iea171e0d0fd56c48f1c456e08e060a12267e39cc
Reviewed-on: https://dart-review.googlesource.com/51129
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Martin Kustermann
3b057dea98