librustc: De-`@mut` the vtable map
librustc: De-`@mut` the typechecking crate context
librustc: De-`@mut` `llupvars` in the translation crate context
librustc: De-`@mut` the variable counters in the inference context
librustc: De-`@mut` the variable bindings in the inference context
librustc: De-`@mut` `RegionVarBindings::constraints`
librustc: De-`@mut` `RegionVarBindings::skolemization_count`
librustc: De-`@mut` `RegionVarBindings::bound_count`
librustc: De-`@mut` `glbs` and `lubs` in `RegionVarBindings`
librustc: De-`@mut` the undo log in `RegionVarBindings`
librustc: De-`@mut` `RegionVarBindings::values`
librustc: De-`@mut` `RegionVarBindings::var_origins`
librustc: De-`@mut` `RegionVarBindings`
librustc: De-`@mut` the inference context
librustc: De-`@mut` `llargs` and `lllocals` in the function context
libextra: Stop using `@mut MemWriter` in the EBML module
librustc: De-`@mut` `break_ln` and `cont_ln` in liveness
librustc: De-`@mut` `used_unsafe` in the type context
librustc: De-`@mut` the named region map in the type context
librustc: Remove the unused `stmt_map` from the borrow checker