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

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-support

Author: Igor Kudrin (igorkudrin)

<details>
<summary>Changes</summary>

This implements a post-commit suggestion for #<!-- -->75679.

---
Full diff: https://github.com/llvm/llvm-project/pull/75973.diff


1 Files Affected:

- (modified) llvm/lib/Support/CommandLine.cpp (+1-2) 


``````````diff
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;

``````````

</details>


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