[clang-move] Fix unit tests with forward slash as separator on windows

Also remove a comment that seems to be left behind.

Differential Revision: https://reviews.llvm.org/D113269

Author: mstorsjo

clang-tools-extra/unittests/clang-move/ClangMoveTests.cpp

@@ -208,7 +208,9 @@ runClangMoveOnCode(const move::MoveDefinitionSpec &Spec,
                    DeclarationReporter *const Reporter = nullptr) {
   clang::RewriterTestContext Context;
 
-  Context.InMemoryFileSystem->setCurrentWorkingDirectory(WorkingDir);
+  llvm::SmallString<16> Dir(WorkingDir);
+  llvm::sys::path::native(Dir);
+  Context.InMemoryFileSystem->setCurrentWorkingDirectory(Dir);
 
   std::map<llvm::StringRef, clang::FileID> FileToFileID;
 
@@ -224,13 +226,12 @@ runClangMoveOnCode(const move::MoveDefinitionSpec &Spec,
   CreateFiles(TestCCName, CC);
 
   std::map<std::string, tooling::Replacements> FileToReplacements;
-  ClangMoveContext MoveContext = {Spec, FileToReplacements, WorkingDir, "LLVM",
+  ClangMoveContext MoveContext = {Spec, FileToReplacements, Dir.c_str(), "LLVM",
                                   Reporter != nullptr};
 
   auto Factory = std::make_unique<clang::move::ClangMoveActionFactory>(
       &MoveContext, Reporter);
 
- // std::string IncludeArg = Twine("-I" + WorkingDir;
   tooling::runToolOnCodeWithArgs(
       Factory->create(), CC, Context.InMemoryFileSystem,
       {"-std=c++11", "-fparse-all-comments", "-I."}, TestCCName, "clang-move",