Hide some warnings/Fix build

miri/fn_call.rs

@@ -3,6 +3,7 @@
 use rustc::hir::def_id::{DefId, CRATE_DEF_INDEX};
 use rustc::mir;
 use rustc_data_structures::indexed_vec::Idx;
+use rustc_target::spec::abi::Abi;
 use syntax::attr;
 use syntax::codemap::Span;
 

miri/lib.rs

@@ -444,9 +444,9 @@ fn end_region<'a>(
     }
 
     fn validation_op<'a>(
-        ecx: &mut EvalContext<'a, 'mir, 'tcx, Self>,
-        op: ::rustc::mir::ValidationOp,
-        operand: &::rustc::mir::ValidationOperand<'tcx, ::rustc::mir::Place<'tcx>>,
+        _ecx: &mut EvalContext<'a, 'mir, 'tcx, Self>,
+        _op: ::rustc::mir::ValidationOp,
+        _operand: &::rustc::mir::ValidationOperand<'tcx, ::rustc::mir::Place<'tcx>>,
     ) -> EvalResult<'tcx> {
         // FIXME: prevent this from ICEing
         //ecx.validation_op(op, operand)