[llvm] [CommandLine][NFC] Replace 'std::function' with 'function_ref' (PR #75973)

[Igor Kudrin via llvm-commits]

https://github.com/igorkudrin created https://github.com/llvm/llvm-project/pull/75973

This implements a post-commit suggestion for #75679.

>From 2d82555bdcf20e3006efae48d63cdba0bae4f99a Mon Sep 17 00:00:00 2001
From: Igor Kudrin <ikudrin at accesssoftek.com>
Date: Tue, 19 Dec 2023 13:55:18 -0800
Subject: [PATCH] [CommandLine][NFC] Replace 'std::function' with
 'function_ref'

This implements a post-commit suggestion for #75679.
---
 llvm/lib/Support/CommandLine.cpp | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/llvm/lib/Support/CommandLine.cpp b/llvm/lib/Support/CommandLine.cpp
index 00179bc32551fe..368dead4491492 100644
--- a/llvm/lib/Support/CommandLine.cpp
+++ b/llvm/lib/Support/CommandLine.cpp
@@ -175,8 +175,7 @@ class CommandLineParser {
                                StringRef Overview, raw_ostream *Errs = nullptr,
                                bool LongOptionsUseDoubleDash = false);
 
-  void forEachSubCommand(Option &Opt,
-                         std::function<void(SubCommand &)> Action) {
+  void forEachSubCommand(Option &Opt, function_ref<void(SubCommand &)> Action) {
     if (Opt.Subs.empty()) {
       Action(SubCommand::getTopLevel());
       return;