Canonicalize some free functions (1) equal

Author: phimuemue

src/lib.rs

@@ -3490,17 +3490,7 @@ pub fn equal<I, J>(a: I, b: J) -> bool
           J: IntoIterator,
           I::Item: PartialEq<J::Item>
 {
-    let mut ia = a.into_iter();
-    let mut ib = b.into_iter();
-    loop {
-        match ia.next() {
-            Some(x) => match ib.next() {
-                Some(y) => if x != y { return false; },
-                None => return false,
-            },
-            None => return ib.next().is_none()
-        }
-    }
+    a.into_iter().eq(b)
 }
 
 /// Assert that two iterables produce equal sequences, with the same