Remove unused clobbers vector

Author: Amanieu

src/ion/data_structures.rs

@@ -293,7 +293,6 @@ pub struct Env<'a, F: Function> {
     pub vreg_regs: Vec<VReg>,
     pub pregs: Vec<PRegData>,
     pub allocation_queue: PrioQueue,
-    pub clobbers: Vec<Inst>,   // Sorted list of insts with clobbers.
     pub safepoints: Vec<Inst>, // Sorted list of safepoint insts.
     pub safepoints_per_vreg: HashMap<usize, HashSet<Inst>>,
 

src/ion/liveranges.rs

@@ -448,10 +448,6 @@ impl<'a, F: Function> Env<'a, F> {
             // For each instruction, in reverse order, process
             // operands and clobbers.
             for inst in insns.rev().iter() {
-                if self.func.inst_clobbers(inst).len() > 0 {
-                    self.clobbers.push(inst);
-                }
-
                 // Mark clobbers with CodeRanges on PRegs.
                 for i in 0..self.func.inst_clobbers(inst).len() {
                     // don't borrow `self`
@@ -1234,7 +1230,6 @@ impl<'a, F: Function> Env<'a, F> {
             }
         }
 
-        self.clobbers.sort_unstable();
         self.blockparam_ins.sort_unstable();
         self.blockparam_outs.sort_unstable();
         self.prog_move_srcs.sort_unstable_by_key(|(pos, _)| *pos);

src/ion/mod.rs

@@ -62,7 +62,6 @@ impl<'a, F: Function> Env<'a, F> {
             vreg_regs: Vec::with_capacity(n),
             pregs: vec![],
             allocation_queue: PrioQueue::new(),
-            clobbers: vec![],
             safepoints: vec![],
             safepoints_per_vreg: HashMap::new(),
             spilled_bundles: vec![],