[clang][DependencyScanning] Use structured bindings for initVFSForByNameScanning (NFC) (#172335)

Author: naveen-seth

clang/lib/DependencyScanning/DependencyScanningWorker.cpp

@@ -170,15 +170,11 @@ bool DependencyScanningWorker::computeDependencies(
 
 bool DependencyScanningWorker::initializeCompilerInstanceWithContext(
     StringRef CWD, ArrayRef<std::string> CommandLine, DiagnosticConsumer &DC) {
-  auto OverlayFSAndArgs =
+  auto [OverlayFS, ModifiedCommandLine] =
       initVFSForByNameScanning(DepFS, CommandLine, CWD, "ScanningByName");
-  auto &OverlayFS = OverlayFSAndArgs.first;
-  const auto &ModifiedCommandLine = OverlayFSAndArgs.second;
-
   auto DiagEngineWithCmdAndOpts =
       std::make_unique<DiagnosticsEngineWithDiagOpts>(ModifiedCommandLine,
                                                       OverlayFS, DC);
-
   return initializeCompilerInstanceWithContext(
       CWD, ModifiedCommandLine, std::move(DiagEngineWithCmdAndOpts), OverlayFS);
 }

clang/lib/Tooling/DependencyScanningTool.cpp

@@ -235,11 +235,8 @@ DependencyScanningTool::initializeCompilerInstanceWithContextOrError(
   // The input command line is either a driver-style command line, or
   // ill-formed. In this case, we will first call the Driver to build a -cc1
   // command line for this compilation or diagnose any ill-formed input.
-  auto OverlayFSAndArgs = initVFSForByNameScanning(
+  auto [OverlayFS, ModifiedCommandLine] = initVFSForByNameScanning(
       &Worker.getVFS(), CommandLine, CWD, "ScanningByName");
-  auto &OverlayFS = OverlayFSAndArgs.first;
-  const auto &ModifiedCommandLine = OverlayFSAndArgs.second;
-
   auto DiagEngineWithCmdAndOpts =
       std::make_unique<DiagnosticsEngineWithDiagOpts>(
           ModifiedCommandLine, OverlayFS, DiagPrinterWithOS->DiagPrinter);