Abstract out fetching of break_address in debug mode

src/arm/assembler-arm.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 763 matching lines @@
   }
 
   // Return the code target address at a call site from the return address
   // of that call in the instruction stream.
   INLINE(static Address target_address_from_return_address(Address pc));
 
   // Given the address of the beginning of a call, return the address
   // in the instruction stream that the call will return from.
   INLINE(static Address return_address_from_call_start(Address pc));
 
+  // Return the code target address of the patch debug break slot
+  INLINE(static Address break_address_from_return_address(Address pc));
+
   // This sets the branch destination (which is in the constant pool on ARM).
   // This is for calls and branches within generated code.
   inline static void deserialization_set_special_target_at(
       Address constant_pool_entry, Code* code, Address target);
 
   // Here we are patching the address in the constant pool, not the actual call
   // instruction.  The address in the constant pool is the same size as a
   // pointer.
   static const int kSpecialTargetSize = kPointerSize;
 
@@ skipping 830 matching lines @@
  public:
   explicit EnsureSpace(Assembler* assembler) {
     assembler->CheckBuffer();
   }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_ASSEMBLER_ARM_H_