[llvm] [ADT] Use DenseMap::contains in EquivalenceClasses.h (NFC) (PR #161120)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/161120

While I am at it, this patch adds [[nodiscard]].


>From bc4d0b91575a6fc9e4b4dfb8ec559142dbac6b2e Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Sat, 27 Sep 2025 23:48:53 -0700
Subject: [PATCH] [ADT] Use DenseMap::contains in EquivalenceClasses.h (NFC)

While I am at it, this patch adds [[nodiscard]].
---
 llvm/include/llvm/ADT/EquivalenceClasses.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/llvm/include/llvm/ADT/EquivalenceClasses.h b/llvm/include/llvm/ADT/EquivalenceClasses.h
index 1a2331c1a0322..7df0d1557af87 100644
--- a/llvm/include/llvm/ADT/EquivalenceClasses.h
+++ b/llvm/include/llvm/ADT/EquivalenceClasses.h
@@ -180,8 +180,8 @@ template <class ElemTy> class EquivalenceClasses {
   }
 
   /// Returns true if \p V is contained an equivalence class.
-  bool contains(const ElemTy &V) const {
-    return TheMapping.find(V) != TheMapping.end();
+  [[nodiscard]] bool contains(const ElemTy &V) const {
+    return TheMapping.contains(V);
   }
 
   /// getLeaderValue - Return the leader for the specified value that is in the