Lookup bindings in the latest world

Post-partitioning the executing world age matters for bindings lookup.
JuliaInterpreter currently does not model world age correctly.
That's a bigger issue. However, for now, just look up bindings in the
latest world age, which mostly restores the unpartitioned behavior.

src/interpret.jl

@@ -2,7 +2,7 @@ isassign(frame::Frame) = isassign(frame, frame.pc)
 isassign(frame::Frame, pc::Int) = (pc in frame.framecode.used)
 
 lookup_var(frame::Frame, val::SSAValue) = frame.framedata.ssavalues[val.id]
-lookup_var(frame::Frame, ref::GlobalRef) = getfield(ref.mod, ref.name)
+lookup_var(frame::Frame, ref::GlobalRef) = invokelatest(getfield, ref.mod, ref.name)
 function lookup_var(frame::Frame, slot::SlotNumber)
     val = frame.framedata.locals[slot.id]
     val !== nothing && return val.value