[clang-tidy][NFC] Use C++17 nested namespaces in the clang-tidy folder

Fix applied by running:

run-clang-tidy.py -checks=-*,modernize-concat-nested-namespaces

Differential Revision: https://reviews.llvm.org/D141770

1 files changed, 2 insertions, 6 deletions

diff --git a/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp b/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp
index 6afe8fe..2fa7cd0 100644
--- a/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp
+++ b/clang-tools-extra/clang-tidy/performance/UnnecessaryValueParamCheck.cpp
@@ -20,9 +20,7 @@
 
 using namespace clang::ast_matchers;
 
-namespace clang {
-namespace tidy {
-namespace performance {
+namespace clang::tidy::performance {
 
 namespace {
 
@@ -193,6 +191,4 @@ void UnnecessaryValueParamCheck::handleMoveFix(const ParmVarDecl &Var,
               SM.getFileID(CopyArgument.getBeginLoc()), "<utility>");
 }
 
-} // namespace performance
-} // namespace tidy
-} // namespace clang
+} // namespace clang::tidy::performance