Use LLVM args to handle -malign-double option

include/clang/Basic/TargetOptions.h

 //===--- TargetOptions.h ----------------------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 27 matching lines @@
 
   /// If given, the version string of the linker in use.
   std::string LinkerVersion;
 
   /// \brief The list of target specific features to enable or disable, as written on the command line.
   std::vector<std::string> FeaturesAsWritten;
 
   /// The list of target specific features to enable or disable -- this should
   /// be a list of strings starting with by '+' or '-'.
   std::vector<std::string> Features;
+
+  // @LOCALMOD-START
+  /// \brief A list of arguments to forward to LLVM's option processing; this
+  /// should only be used for debugging and experimental features.
+  std::vector<std::string> LLVMArgs;
+  // @LOCALMOD-END
 };
 
 }  // end namespace clang
 
 #endif