Use None consistently (NFC)

This patch replaces NoneType() and NoneType::None with None in
preparation for migration from llvm::Optional to std::optional.

In the std::optional world, we are not guranteed to be able to
default-construct std::nullopt_t or peek what's inside it, so neither
NoneType() nor NoneType::None has a corresponding expression in the
std::optional world.

Once we consistently use None, we should even be able to replace the
contents of llvm/include/llvm/ADT/None.h with something like:

  using NoneType = std::nullopt_t;
  inline constexpr std::nullopt_t None = std::nullopt;

to ease the migration from llvm::Optional to std::optional.

Differential Revision: https://reviews.llvm.org/D138376

1 files changed, 2 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
index 05969e4..2a16203 100644
--- a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -428,8 +428,7 @@ static bool removeRedundantDbgInstrsUsingForwardScan(BasicBlock *BB) {
       VariableMap;
   for (auto &I : *BB) {
     if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(&I)) {
-      DebugVariable Key(DVI->getVariable(),
-                        NoneType(),
+      DebugVariable Key(DVI->getVariable(), None,
                         DVI->getDebugLoc()->getInlinedAt());
       auto VMI = VariableMap.find(Key);
       auto *DAI = dyn_cast<DbgAssignIntrinsic>(DVI);
@@ -490,7 +489,7 @@ static bool remomveUndefDbgAssignsFromEntryBlock(BasicBlock *BB) {
   DenseSet<DebugVariable> SeenDefForAggregate;
   // Returns the DebugVariable for DVI with no fragment info.
   auto GetAggregateVariable = [](DbgValueInst *DVI) {
-    return DebugVariable(DVI->getVariable(), NoneType(),
+    return DebugVariable(DVI->getVariable(), None,
                          DVI->getDebugLoc()->getInlinedAt());
   };