[CodeGen] Use std::nullopt instead of None (NFC)

This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/LiveDebugVariables.cpp b/llvm/lib/CodeGen/LiveDebugVariables.cpp
index 574c0f9..f514f40 100644
--- a/llvm/lib/CodeGen/LiveDebugVariables.cpp
+++ b/llvm/lib/CodeGen/LiveDebugVariables.cpp
@@ -985,7 +985,7 @@ void UserValue::extendDef(
     Start = Start.getNextSlot();
     if (I.value() != DbgValue || I.stop() != Start) {
       // Clear `Kills`, as we have a new def available.
-      Kills = None;
+      Kills = std::nullopt;
       return;
     }
     // This is a one-slot placeholder. Just skip it.
@@ -996,7 +996,7 @@ void UserValue::extendDef(
   if (I.valid() && I.start() < Stop) {
     Stop = I.start();
     // Clear `Kills`, as we have a new def available.
-    Kills = None;
+    Kills = std::nullopt;
   }
 
   if (Start < Stop) {