Fix issues with Arm's use of embedded constant pools

src/x64/assembler-x64.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 686 matching lines @@
   void instruction##q(P1 p1, P2 p2, P3 p3) {            \
     emit_##instruction(p1, p2, p3, kInt64Size);         \
   }
   ASSEMBLER_INSTRUCTION_LIST(DECLARE_INSTRUCTION)
 #undef DECLARE_INSTRUCTION
 
   // Insert the smallest number of nop instructions
   // possible to align the pc offset to a multiple
   // of m, where m must be a power of 2.
   void Align(int m);
+  // Insert the smallest number of zero bytes possible to align the pc offset
+  // to a mulitple of m. m must be a power of 2 (>= 2).
+  void DataAlign(int m);
   void Nop(int bytes = 1);
   // Aligns code to something that's optimal for a jump target for the platform.
   void CodeTargetAlign();
 
   // Stack
   void pushfq();
   void popfq();
 
   void pushq(Immediate value);
   // Push a 32 bit integer, and guarantee that it is actually pushed as a
@@ skipping 1439 matching lines @@
  private:
   Assembler* assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_ASSEMBLER_X64_H_