bochs: restore original RIP increase behavior

The now commented-out variant that was introduced in commit be9d291
(when FAIL* was still in an SVN repo, r1702) may be necessary for some
specific system behavior after modifying the currently executed
instruction, but breaks random-jump FI (import-trace -i
RandomJumpImporter).

Change-Id: I1ef3dc6dceab66b01cddd988e0f201065e404f99

simulators/bochs/cpu/cpu.cc

@@ -151,16 +151,22 @@ void BX_CPU_C::cpu_loop(Bit32u max_instr_count)
         debug_disasm_instruction(BX_CPU_THIS_PTR prev_rip);
       }
 #endif
+#if 0
       // DanceOS: Save original instruction length in case we modify the instruction.
       unsigned orig_len = i->ilen();
+#endif
       // DanceOS: Aspect "hook"
       defineCPULoopJoinPoint(BX_CPU_THIS, i);
 
       // instruction decoding completed -> continue with execution
       // want to allow changing of the instruction inside instrumentation callback
       BX_INSTR_BEFORE_EXECUTION(BX_CPU_ID, i);
+#if 0
       // DanceOS: Use original length (see above).
       RIP += orig_len;
+#else
+      RIP += i->ilen();
+#endif
       BX_CPU_CALL_METHOD(i->execute, (i)); // might iterate repeat instruction
       BX_CPU_THIS_PTR prev_rip = RIP; // commit new RIP
       BX_INSTR_AFTER_EXECUTION(BX_CPU_ID, i);