Fix logic around comparison

Author: Azoy

stdlib/public/Synchronization/Atomics/WordPair.swift

@@ -191,7 +191,11 @@ extension WordPair: Comparable {
   @_alwaysEmitIntoClient
   @_transparent
   public func <(lhs: WordPair, rhs: WordPair) -> Bool {
-    lhs.first < rhs.first || lhs.second < rhs.second
+    if lhs.first != rhs.first {
+      return lhs.first < rhs.first
+    } else {
+      return lhs.second < rhs.second
+    }
   }
 }
 

test/stdlib/Synchronization/Atomics/WordPair.swift

@@ -50,11 +50,15 @@ suite.test("basics") {
   let c1 = WordPair(first: 1, second: 0)
   let c2 = WordPair(first: 2, second: 0)
   let c3 = WordPair(first: 0, second: 1)
+  let c4 = WordPair(first: 1, second: 2)
+  let c5 = WordPair(first: 2, second: 1)
   expectFalse(c0 < c0)
   expectTrue(c0 < c1)
   expectTrue(c0 < c2)
   expectTrue(c0 < c3)
   expectFalse(c1 < c0)
+  expectTrue(c4 < c5)
+  expectFalse(c5 < c4)
 }
 
 } // if #available(SwiftStdlib 6.0, *)