rustc_const_eval: remove ref patterns (+some pattern matching imps)

compiler/rustc_const_eval/src/const_eval/error.rs

@@ -36,16 +36,16 @@ impl<'tcx> Into<InterpErrorInfo<'tcx>> for ConstEvalErrKind {
 impl fmt::Display for ConstEvalErrKind {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         use self::ConstEvalErrKind::*;
-        match *self {
+        match self {
             ConstAccessesStatic => write!(f, "constant accesses static"),
             ModifiedGlobal => {
                 write!(f, "modifying a static's initial value from another static's initializer")
             }
-            AssertFailure(ref msg) => write!(f, "{:?}", msg),
+            AssertFailure(msg) => write!(f, "{:?}", msg),
             Panic { msg, line, col, file } => {
                 write!(f, "the evaluated program panicked at '{}', {}:{}:{}", msg, file, line, col)
             }
-            Abort(ref msg) => write!(f, "{}", msg),
+            Abort(msg) => write!(f, "{}", msg),
         }
     }
 }

compiler/rustc_const_eval/src/const_eval/eval_queries.rs

@@ -167,7 +167,7 @@ pub(super) fn op_to_const<'tcx>(
         }
     };
     match immediate {
-        Left(ref mplace) => to_const_value(mplace),
+        Left(mplace) => to_const_value(&mplace),
         // see comment on `let try_as_immediate` above
         Right(imm) => match *imm {
             _ if imm.layout.is_zst() => ConstValue::ZeroSized,

compiler/rustc_const_eval/src/const_eval/machine.rs

@@ -533,7 +533,7 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
         let eval_to_int =
             |op| ecx.read_immediate(&ecx.eval_operand(op, None)?).map(|x| x.to_const_int());
         let err = match msg {
-            BoundsCheck { ref len, ref index } => {
+            BoundsCheck { len, index } => {
                 let len = eval_to_int(len)?;
                 let index = eval_to_int(index)?;
                 BoundsCheck { len, index }