[Interpreter] Allocates new temporary register outside the reservation for consecutive registers.

test/cctest/interpreter/test-bytecode-generator.cc

 // Copyright 2015 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"
 
 #include "src/compiler.h"
 #include "src/interpreter/bytecode-array-iterator.h"
 #include "src/interpreter/bytecode-generator.h"
 #include "src/interpreter/interpreter.h"
@@ skipping 5565 matching lines @@
            B(LdaSmi8), U8(2),   //
            B(Star), R(1),       //
            B(Mul), R(4),        //
            B(Add), R(3),        //
            B(Star), R(4),       //
            B(LdaSmi8), U8(3),   //
            B(Star), R(1),       //
            B(Add), R(4),        //
            B(Star), R(3),       //
            B(LdaSmi8), U8(4),   //
+           B(Star), R(5),       //
+           B(Add), R(3),        //
            B(Star), R(4),       //
-           B(Add), R(3),        //
-           B(Star), R(5),       //
            B(LdaSmi8), U8(5),   //
            B(Star), R(1),       //
-           B(Add), R(5),        //
+           B(Add), R(4),        //
            B(Star), R(3),       //
            B(Ldar), R(1),       //
            B(Add), R(3),        //
-           B(Mov), R(4), R(0),  //
+           B(Mov), R(5), R(0),  //
            B(Return),           //
        },
        0},
       {"var x = 17;\n"
        "return 1 + x + (x++) + (++x);\n",
        5 * kPointerSize,
        1,
        40,
        {
            B(LdaSmi8), U8(17),  //
@@ skipping 24 matching lines @@
   for (size_t i = 0; i < arraysize(snippets); i++) {
     Handle<BytecodeArray> bytecode_array =
         helper.MakeBytecodeForFunctionBody(snippets[i].code_snippet);
     CheckBytecodeArrayEqual(snippets[i], bytecode_array);
   }
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8