[Transforms] 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, 1 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Scalar/Float2Int.cpp b/llvm/lib/Transforms/Scalar/Float2Int.cpp
index 56f2a3b..432d53e 100644
--- a/llvm/lib/Transforms/Scalar/Float2Int.cpp
+++ b/llvm/lib/Transforms/Scalar/Float2Int.cpp
@@ -243,7 +243,7 @@ Optional<ConstantRange> Float2IntPass::calcRange(Instruction *I) {
       auto OpIt = SeenInsts.find(OI);
       assert(OpIt != SeenInsts.end() && "def not seen before use!");
       if (OpIt->second == unknownRange())
-        return None; // Wait until operand range has been calculated.
+        return std::nullopt; // Wait until operand range has been calculated.
       OpRanges.push_back(OpIt->second);
     } else if (ConstantFP *CF = dyn_cast<ConstantFP>(O)) {
       // Work out if the floating point number can be losslessly represented