move the drop expansion code to rustc_mir

Author: arielb1

src/librustc_borrowck/borrowck/mir/dataflow/graphviz.rs

@@ -15,6 +15,7 @@ use rustc::mir::{BasicBlock, Mir};
 use rustc_data_structures::bitslice::bits_to_string;
 use rustc_data_structures::indexed_set::{IdxSet};
 use rustc_data_structures::indexed_vec::Idx;
+use rustc_mir::util as mir_util;
 
 use dot;
 use dot::IntoCow;
@@ -219,7 +220,7 @@ impl<'a, 'tcx, MWF, P> dot::Labeller<'a> for Graph<'a, 'tcx, MWF, P>
             }
             Ok(())
         }
-        ::rustc_mir::graphviz::write_node_label(
+        mir_util::write_graphviz_node_label(
             *n, self.mbcx.mir(), &mut v, 4,
             |w| {
                 let flow = self.mbcx.flow_state();

src/librustc_borrowck/borrowck/mir/dataflow/impls.rs

@@ -14,10 +14,10 @@ use rustc_data_structures::bitslice::BitSlice; // adds set_bit/get_bit to &[usiz
 use rustc_data_structures::bitslice::{BitwiseOperator};
 use rustc_data_structures::indexed_set::{IdxSet};
 use rustc_data_structures::indexed_vec::Idx;
+use rustc_mir::util::elaborate_drops::DropFlagState;
 
 use super::super::gather_moves::{HasMoveData, MoveData, MoveOutIndex, MovePathIndex};
 use super::super::MoveDataParamEnv;
-use super::super::DropFlagState;
 use super::super::drop_flag_effects_for_function_entry;
 use super::super::drop_flag_effects_for_location;
 use super::super::on_lookup_result_bits;