Made the detailed reason for deopts mandatory on ia32. Unified and improved things.

src/x64/code-stubs-x64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
@@ skipping 300 matching lines @@
     __ jmp(&int_exponent);
 
     __ bind(&exponent_not_smi);
     __ movsd(double_exponent, FieldOperand(exponent, HeapNumber::kValueOffset));
   }
 
   if (exponent_type() != INTEGER) {
     Label fast_power, try_arithmetic_simplification;
     // Detect integer exponents stored as double.
     __ DoubleToI(exponent, double_exponent, double_scratch,
-                 TREAT_MINUS_ZERO_AS_ZERO, &try_arithmetic_simplification);
+                 TREAT_MINUS_ZERO_AS_ZERO, &try_arithmetic_simplification,
+                 &try_arithmetic_simplification,
+                 &try_arithmetic_simplification);
     __ jmp(&int_exponent);
 
     __ bind(&try_arithmetic_simplification);
     __ cvttsd2si(exponent, double_exponent);
     // Skip to runtime if possibly NaN (indicated by the indefinite integer).
     __ cmpl(exponent, Immediate(0x1));
     __ j(overflow, &call_runtime);
 
     if (exponent_type() == ON_STACK) {
       // Detect square root case.  Crankshaft detects constant +/-0.5 at
@@ skipping 4334 matching lines @@
                               return_value_operand,
                               NULL);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64