[ADT] Remove ArrayRef(std::nullopt_t)

[kazutakahirata]

ArrayRef(std::nullopt_t) has been deprecated since:

commit 2529de5
Author: Kazu Hirata kazu@google.com
Date: Fri Jun 27 01:03:02 2025 -0700

Note that we've made at lease one release, llvmorg-21.1, with this
deprecation.

[llvmbot]

@llvm/pr-subscribers-llvm-adt

Author: Kazu Hirata (kazutakahirata)

Changes

ArrayRef(std::nullopt_t) has been deprecated since:

commit 2529de5
Author: Kazu Hirata <kazu@google.com>
Date: Fri Jun 27 01:03:02 2025 -0700

Note that we've made at lease one release, llvmorg-21.1, with this
deprecation.

---

Full diff: https://github.com/llvm/llvm-project/pull/165831.diff

1 Files Affected:

• (modified) llvm/include/llvm/ADT/ArrayRef.h (-4)

diff --git a/llvm/include/llvm/ADT/ArrayRef.h b/llvm/include/llvm/ADT/ArrayRef.h
index 448d10013d371..450f4d04c97fc 100644
--- a/llvm/include/llvm/ADT/ArrayRef.h
+++ b/llvm/include/llvm/ADT/ArrayRef.h
@@ -66,10 +66,6 @@ namespace llvm {
     /// Construct an empty ArrayRef.
     /*implicit*/ ArrayRef() = default;
 
-    /// Construct an empty ArrayRef from std::nullopt.
-    /*implicit*/ LLVM_DEPRECATED("Use {} or ArrayRef<T>() instead", "{}")
-    ArrayRef(std::nullopt_t) {}
-
     /// Construct an ArrayRef from a single element.
     /*implicit*/ ArrayRef(const T &OneElt LLVM_LIFETIME_BOUND)
         : Data(&OneElt), Length(1) {}