Fix issues with Arm's use of embedded constant pools

src/arm/assembler-arm.cc

 // 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 476 matching lines @@
   desc->instr_size = pc_offset();
   desc->reloc_size = (buffer_ + buffer_size_) - reloc_info_writer.pos();
   desc->constant_pool_size =
       (constant_pool_offset ? desc->instr_size - constant_pool_offset : 0);
   desc->origin = this;
 }
 
 
 void Assembler::Align(int m) {
   DCHECK(m >= 4 && base::bits::IsPowerOfTwo32(m));
+  DCHECK((pc_offset() & (kInstrSize - 1)) == 0);
   while ((pc_offset() & (m - 1)) != 0) {
     nop();
   }
 }
 
 
 void Assembler::CodeTargetAlign() {
   // Preferred alignment of jump targets on some ARM chips.
   Align(8);
 }
@@ skipping 3443 matching lines @@
     DCHECK(is_uint12(offset));
     instr_at_put(pc, SetLdrRegisterImmediateOffset(instr, offset));
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM