[tools] 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/tools/llvm-cov/SourceCoverageViewText.cpp b/llvm/tools/llvm-cov/SourceCoverageViewText.cpp
index 5f3eca3..6755619 100644
--- a/llvm/tools/llvm-cov/SourceCoverageViewText.cpp
+++ b/llvm/tools/llvm-cov/SourceCoverageViewText.cpp
@@ -128,7 +128,7 @@ void SourceCoverageViewText::renderLine(raw_ostream &OS, LineRef L,
     else if (Col == ExpansionCol)
       Highlight = raw_ostream::CYAN;
     else
-      Highlight = None;
+      Highlight = std::nullopt;
   }
 
   // Show the rest of the line.