Fix build with --no-default-features

Author: keithw

crates/wasmparser/src/readers/core/elements.rs

@@ -123,7 +123,8 @@ impl<'a> FromReader<'a> for Element<'a> {
             let mut allocs = OperatorsReaderAllocations::default();
             if exprs {
                 for _ in 0..items_count {
-                    let mut ops = OperatorsReader::new(reader.clone(), std::mem::take(&mut allocs));
+                    let mut ops =
+                        OperatorsReader::new(reader.clone(), core::mem::take(&mut allocs));
                     ops.skip_const_expr()?;
                     *reader = ops.get_binary_reader();
                     allocs = ops.into_allocations();

crates/wasmparser/src/readers/core/operators.rs

@@ -1014,6 +1014,7 @@ macro_rules! define_visit_operator_stack_adapter {
 impl<'x, 'a, T: VisitOperator<'a>> VisitOperator<'a> for FrameStackAdapter<'x, 'a, T> {
     type Output = T::Output;
 
+    #[cfg(feature = "simd")]
     fn simd_visitor(&mut self) -> Option<&mut dyn VisitSimdOperator<'a, Output = Self::Output>> {
         self.visitor.simd_visitor()
     }
@@ -1034,6 +1035,7 @@ macro_rules! define_passthrough_visit_operator {
 impl<'x, 'a, T: VisitOperator<'a>> VisitOperator<'a> for SingleFrameAdapter<'x, 'a, T> {
     type Output = T::Output;
 
+    #[cfg(feature = "simd")]
     fn simd_visitor(&mut self) -> Option<&mut dyn VisitSimdOperator<'a, Output = Self::Output>> {
         self.visitor.simd_visitor()
     }