Rebased localmods in clang to 223109.

lib/CodeGen/TargetInfo.h

 //===---- TargetInfo.h - Encapsulate target details -------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // These classes wrap the information about a call or function
@@ skipping 201 matching lines @@
   /// platform.
   virtual void getDependentLibraryOption(llvm::StringRef Lib,
                                          llvm::SmallString<24> &Opt) const;
 
   /// Gets the linker options necessary to detect object file mismatches on
   /// this platform.
   virtual void getDetectMismatchOption(llvm::StringRef Name,
                                        llvm::StringRef Value,
                                        llvm::SmallString<32> &Opt) const {}
 
+  // @LOCALMOD-START
+  /// Determine whether the sequentially consistent fence generated for
+  /// the legacy GCC-style ``__sync_synchronize()`` builtin should be
+  /// surrounded by empty assembly directives which touch all of
+  /// memory. This allows platforms which aim for portability to
+  /// isolate themselves from changes in sequentially consistent
+  /// fence's semantics, since its intent is to represent the
+  /// C11/C++11 memory model which only orders atomic memory accesses.
+  /// This won't guarantee that all accesses (e.g. those to
+  /// non-escaping objects) will not be reordered.
+  virtual bool addAsmMemoryAroundSyncSynchronize() const {
+    return false;
+  }
+
+  /// Determine whether a full sequentially consistent fence should be
+  /// emitted when ``asm("":::"memory")`` is encountered, treating it
+  /// like ``__sync_synchronize()``.
+  virtual bool asmMemoryIsFence() const {
+    return false;
+  }
+  // @LOCALMOD-END
+
   /// Gets the target-specific default alignment used when an 'aligned' clause
   /// is used with a 'simd' OpenMP directive without specifying a specific
   /// alignment.
   virtual unsigned getOpenMPSimdDefaultAlignment(QualType Type) const {
     return 0;
   }
 };
 }
 
 #endif