Don't generate a shift left by one if can deoptimize on ia32 and arm and mips.

src/arm/lithium-codegen-arm.cc

 // Copyright 2012 the V8 project authors. 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.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1726 matching lines @@
             __ tst(left, Operand(0x80000000));
             DeoptimizeIf(ne, instr->environment());
           }
           __ Move(result, left);
         }
         break;
       case Token::SHL:
         if (shift_count != 0) {
           if (instr->hydrogen_value()->representation().IsSmi() &&
               instr->can_deopt()) {
-            __ mov(result, Operand(left, LSL, shift_count - 1));
+            if (shift_count != 1) {
+              __ mov(result, Operand(left, LSL, shift_count - 1));
+            }
             __ SmiTag(result, result, SetCC);
             DeoptimizeIf(vs, instr->environment());
           } else {
             __ mov(result, Operand(left, LSL, shift_count));
           }
         } else {
           __ Move(result, left);
         }
         break;
       default:
@@ skipping 4078 matching lines @@
   __ sub(scratch, result, Operand::PointerOffsetFromSmiKey(index));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal