Tidy up calls to analyze_branch.

lib/cretonne/src/regalloc/coloring.rs

@@ -908,7 +908,7 @@ impl<'a> Context<'a> {
 
         let inst = self.cur.current_inst().expect("Not on an instruction");
         let ctx = self.liveness.context(&self.cur.func.layout);
-        match self.cur.func.dfg[inst].analyze_branch(&self.cur.func.dfg.value_lists) {
+        match self.cur.func.dfg.analyze_branch(inst) {
             NotABranch => false,
             SingleDest(ebb, _) => {
                 let lr = &self.liveness[value];

lib/cretonne/src/regalloc/live_value_tracker.rs

@@ -260,7 +260,7 @@ impl LiveValueTracker {
     ) -> (&[LiveValue], &[LiveValue], &[LiveValue]) {
         // Save a copy of the live values before any branches or jumps that could be somebody's
         // immediate dominator.
-        match dfg[inst].analyze_branch(&dfg.value_lists) {
+        match dfg.analyze_branch(inst) {
             BranchInfo::NotABranch => {}
             _ => self.save_idom_live_set(inst),
         }