Modernize some low-hanging PathV1 uses.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183903 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ARCMigrate/FileRemapper.cpp b/lib/ARCMigrate/FileRemapper.cpp
index 14fa179..ee33c8f 100644
--- a/lib/ARCMigrate/FileRemapper.cpp
+++ b/lib/ARCMigrate/FileRemapper.cpp
@@ -14,7 +14,6 @@
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"
-#include "llvm/Support/PathV1.h"
 #include "llvm/Support/raw_ostream.h"
 #include <fstream>
 
@@ -44,10 +43,9 @@
 
 std::string FileRemapper::getRemapInfoFile(StringRef outputDir) {
   assert(!outputDir.empty());
-  llvm::sys::Path dir(outputDir);
-  llvm::sys::Path infoFile = dir;
-  infoFile.appendComponent("remap");
-  return infoFile.str();
+  SmallString<128> InfoFile = outputDir;
+  llvm::sys::path::append(InfoFile, "remap");
+  return InfoFile.str();
 }
 
 bool FileRemapper::initFromDisk(StringRef outputDir, DiagnosticsEngine &Diag,