zip: Add Zip::and_unchecked and use to skip redundant dimension check

This speeds up the benches/append.rs benchmarks by 5-10%.

Author: bluss

src/impl_owned_array.rs

@@ -540,7 +540,10 @@ impl<A, D> Array<A, D>
                 data: &mut self.data,
             };
 
-            Zip::from(tail_view).and(array)
+
+            // Safety: tail_view is constructed to have the same shape as array
+            Zip::from(tail_view)
+                .and_unchecked(array)
                 .debug_assert_c_order()
                 .for_each(|to, from| {
                     to.write(from.clone());

src/zip/mod.rs

@@ -679,6 +679,26 @@ macro_rules! map_impl {
                 self.build_and(part)
             }
 
+            /// Include the producer `p` in the Zip.
+            ///
+            /// ## Safety
+            ///
+            /// The caller must ensure that the producer's shape is equal to the Zip's shape.
+            /// Uses assertions when debug assertions are enabled.
+            #[allow(unused)]
+            pub(crate) unsafe fn and_unchecked<P>(self, p: P) -> Zip<($($p,)* P::Output, ), D>
+                where P: IntoNdProducer<Dim=D>,
+            {
+                #[cfg(debug_assertions)]
+                {
+                    self.and(p)
+                }
+                #[cfg(not(debug_assertions))]
+                {
+                    self.build_and(p.into_producer())
+                }
+            }
+
             /// Include the producer `p` in the Zip, broadcasting if needed.
             ///
             /// If their shapes disagree, `rhs` is broadcast to the shape of `self`.