make trans contexts into objects

[graydon]

Nobody should have to write cx.fcx.lcx.ccx.tcx. Everyone winces when they see it. Fix this. Put the contexts in objects that pick such things up from their parents. No functional changes, just a whole lot of shoving stuff around.

[pcwalton]

I thought this was dependent on object fields.

[lkuper]

Does it make sense for create_llargs_for_fn_args, new_fn_ctxt, trans_args, and type_of_fn_full to be methods on these objects?

[graydon]

Could do. Start with the simpler version though (just getting rid of all the reaching.endlessly.through.dots) and move things into objs in later commits, as taste dictates.

[pcwalton]

Another possibility for now: make accessors that remove all the cx.fcx.lcx.ccx.tcx duplication.

[graydon]

pcwalton: that's what I meant

[marijnh]

I guess this is no longer relevant. We have accessors. There doesn't seem to be a reason to pay vtable overhead for these contexts.