[lld] Mark operator== const to avoid ambiguity in C++20. (PR #68119)

[Samira Bazuzi via llvm-commits]

https://github.com/bazuzi created https://github.com/llvm/llvm-project/pull/68119

C++20 will automatically generate an operator== with reversed operand order, which is ambiguous with the written operator== when one argument is marked const and the other isn't.

>From 4667528ee8f997ce62d83d916064f12b296bab0d Mon Sep 17 00:00:00 2001
From: Samira Bazuzi <bazuzi at google.com>
Date: Tue, 3 Oct 2023 11:37:10 -0400
Subject: [PATCH] Mark operator== const to avoid ambiguity in C++20.

C++20 will automatically generate an operator== with reversed operand order, which is ambiguous with the written operator== when one argument is marked const and the other isn't.
---
 lld/COFF/Config.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lld/COFF/Config.h b/lld/COFF/Config.h
index e66ab3a32c56721..ff87eab2744dd51 100644
--- a/lld/COFF/Config.h
+++ b/lld/COFF/Config.h
@@ -72,7 +72,7 @@ struct Export {
   StringRef symbolName;
   StringRef exportName; // Name in DLL
 
-  bool operator==(const Export &e) {
+  bool operator==(const Export &e) const {
     return (name == e.name && extName == e.extName &&
             aliasTarget == e.aliasTarget &&
             ordinal == e.ordinal && noname == e.noname &&