Index: clang/include/clang/Frontend/ASTUnit.h
===================================================================
--- clang/include/clang/Frontend/ASTUnit.h
+++ clang/include/clang/Frontend/ASTUnit.h
@@ -688,14 +688,15 @@
   /// lifetime is expected to extend past that of the returned ASTUnit.
   ///
   /// \returns - The initialized ASTUnit or null if the AST failed to load.
-  static std::unique_ptr<ASTUnit> LoadFromASTFile(
-      const std::string &Filename, const PCHContainerReader &PCHContainerRdr,
-      WhatToLoad ToLoad, IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
-      const FileSystemOptions &FileSystemOpts, bool UseDebugInfo = false,
-      bool OnlyLocalDecls = false, ArrayRef<RemappedFile> RemappedFiles = None,
-      CaptureDiagsKind CaptureDiagnostics = CaptureDiagsKind::None,
-      bool AllowPCHWithCompilerErrors = false,
-      bool UserFilesAreVolatile = false);
+  static std::unique_ptr<ASTUnit>
+  LoadFromASTFile(const std::string &Filename,
+                  const PCHContainerReader &PCHContainerRdr, WhatToLoad ToLoad,
+                  IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
+                  const FileSystemOptions &FileSystemOpts,
+                  bool UseDebugInfo = false, bool OnlyLocalDecls = false,
+                  CaptureDiagsKind CaptureDiagnostics = CaptureDiagsKind::None,
+                  bool AllowPCHWithCompilerErrors = false,
+                  bool UserFilesAreVolatile = false);
 
 private:
   /// Helper function for \c LoadFromCompilerInvocation() and
Index: clang/lib/Frontend/ASTUnit.cpp
===================================================================
--- clang/lib/Frontend/ASTUnit.cpp
+++ clang/lib/Frontend/ASTUnit.cpp
@@ -758,9 +758,8 @@
     const std::string &Filename, const PCHContainerReader &PCHContainerRdr,
     WhatToLoad ToLoad, IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
     const FileSystemOptions &FileSystemOpts, bool UseDebugInfo,
-    bool OnlyLocalDecls, ArrayRef<RemappedFile> RemappedFiles,
-    CaptureDiagsKind CaptureDiagnostics, bool AllowPCHWithCompilerErrors,
-    bool UserFilesAreVolatile) {
+    bool OnlyLocalDecls, CaptureDiagsKind CaptureDiagnostics,
+    bool AllowPCHWithCompilerErrors, bool UserFilesAreVolatile) {
   std::unique_ptr<ASTUnit> AST(new ASTUnit(true));
 
   // Recover resources if we crash before exiting this method.
@@ -793,9 +792,6 @@
                                          /*Target=*/nullptr));
   AST->PPOpts = std::make_shared<PreprocessorOptions>();
 
-  for (const auto &RemappedFile : RemappedFiles)
-    AST->PPOpts->addRemappedFile(RemappedFile.first, RemappedFile.second);
-
   // Gather Info for preprocessor construction later on.
 
   HeaderSearch &HeaderInfo = *AST->HeaderInfo;
Index: clang/tools/c-index-test/core_main.cpp
===================================================================
--- clang/tools/c-index-test/core_main.cpp
+++ clang/tools/c-index-test/core_main.cpp
@@ -262,7 +262,7 @@
   std::unique_ptr<ASTUnit> AU = ASTUnit::LoadFromASTFile(
       std::string(modulePath), *pchRdr, ASTUnit::LoadASTOnly, Diags,
       FileSystemOpts, /*UseDebugInfo=*/false,
-      /*OnlyLocalDecls=*/true, None, CaptureDiagsKind::None,
+      /*OnlyLocalDecls=*/true, CaptureDiagsKind::None,
       /*AllowPCHWithCompilerErrors=*/true,
       /*UserFilesAreVolatile=*/false);
   if (!AU) {
Index: clang/tools/libclang/CIndex.cpp
===================================================================
--- clang/tools/libclang/CIndex.cpp
+++ clang/tools/libclang/CIndex.cpp
@@ -3475,7 +3475,7 @@
   std::unique_ptr<ASTUnit> AU = ASTUnit::LoadFromASTFile(
       ast_filename, CXXIdx->getPCHContainerOperations()->getRawReader(),
       ASTUnit::LoadEverything, Diags, FileSystemOpts, /*UseDebugInfo=*/false,
-      CXXIdx->getOnlyLocalDecls(), None, CaptureDiagsKind::All,
+      CXXIdx->getOnlyLocalDecls(), CaptureDiagsKind::All,
       /*AllowPCHWithCompilerErrors=*/true,
       /*UserFilesAreVolatile=*/true);
   *out_TU = MakeCXTranslationUnit(CXXIdx, std::move(AU));