Revert "[VFS] Add reverse iterator to OverlayFileSystem"

This reverts commit a6015a4.

Author: JDevlieghere

include/llvm/Support/VirtualFileSystem.h

@@ -336,24 +336,15 @@ class OverlayFileSystem : public FileSystem {
 
   using iterator = FileSystemList::reverse_iterator;
   using const_iterator = FileSystemList::const_reverse_iterator;
-  using reverse_iterator = FileSystemList::iterator;
-  using const_reverse_iterator = FileSystemList::const_iterator;
 
   /// Get an iterator pointing to the most recently added file system.
   iterator overlays_begin() { return FSList.rbegin(); }
   const_iterator overlays_begin() const { return FSList.rbegin(); }
 
-  /// Get an iterator pointing one-past the least recently added file system.
+  /// Get an iterator pointing one-past the least recently added file
+  /// system.
   iterator overlays_end() { return FSList.rend(); }
   const_iterator overlays_end() const { return FSList.rend(); }
-
-  /// Get an iterator pointing to the least recently added file system.
-  reverse_iterator overlays_rbegin() { return FSList.begin(); }
-  const_reverse_iterator overlays_rbegin() const { return FSList.begin(); }
-
-  /// Get an iterator pointing one-past the most recently added file system.
-  reverse_iterator overlays_rend() { return FSList.end(); }
-  const_reverse_iterator overlays_rend() const { return FSList.end(); }
 };
 
 /// By default, this delegates all calls to the underlying file system. This

unittests/Support/VirtualFileSystemTest.cpp

@@ -343,57 +343,6 @@ TEST(VirtualFileSystemTest, MergedDirPermissions) {
   EXPECT_EQ(0200, Status->getPermissions());
 }
 
-TEST(VirtualFileSystemTest, OverlayIterator) {
-  IntrusiveRefCntPtr<DummyFileSystem> Lower(new DummyFileSystem());
-  Lower->addRegularFile("/foo");
-  IntrusiveRefCntPtr<DummyFileSystem> Upper(new DummyFileSystem());
-
-  IntrusiveRefCntPtr<vfs::OverlayFileSystem> O(
-      new vfs::OverlayFileSystem(Lower));
-  O->pushOverlay(Upper);
-
-  ErrorOr<vfs::Status> Status((std::error_code()));
-  {
-    auto it = O->overlays_begin();
-    auto end = O->overlays_end();
-
-    EXPECT_NE(it, end);
-
-    Status = (*it)->status("/foo");
-    ASSERT_TRUE(Status.getError());
-
-    it++;
-    EXPECT_NE(it, end);
-
-    Status = (*it)->status("/foo");
-    ASSERT_FALSE(Status.getError());
-    EXPECT_TRUE(Status->exists());
-
-    it++;
-    EXPECT_EQ(it, end);
-  }
-
-  {
-    auto it = O->overlays_rbegin();
-    auto end = O->overlays_rend();
-
-    EXPECT_NE(it, end);
-
-    Status = (*it)->status("/foo");
-    ASSERT_FALSE(Status.getError());
-    EXPECT_TRUE(Status->exists());
-
-    it++;
-    EXPECT_NE(it, end);
-
-    Status = (*it)->status("/foo");
-    ASSERT_TRUE(Status.getError());
-
-    it++;
-    EXPECT_EQ(it, end);
-  }
-}
-
 namespace {
 struct ScopedDir {
   SmallString<128> Path;