[Interpreter] Add support for calling runtime functions which return a pair.

src/interpreter/bytecodes.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/interpreter/bytecodes.h"
 
 #include "src/frames.h"
 #include "src/interpreter/bytecode-traits.h"
 
 namespace v8 {
@@ skipping 275 matching lines @@
           if (parameter_index == 0) {
             os << "<this>";
           } else {
             os << "a" << parameter_index - 1;
           }
         } else {
           os << "r" << reg.index();
         }
         break;
       }
+      case interpreter::OperandType::kRegPair8: {
+        Register reg = Register::FromOperand(*operand_start);
+        if (reg.is_parameter()) {
+          int parameter_index = reg.ToParameterIndex(parameter_count);
+          DCHECK_NE(parameter_index, 0);
+          os << "a" << parameter_index - 1 << "-" << parameter_index;
+        } else {
+          os << "r" << reg.index() << "-" << reg.index() + 1;
+        }
+        break;
+      }
       case interpreter::OperandType::kReg16: {
         Register reg =
             Register::FromWideOperand(ReadUnalignedUInt16(operand_start));
         if (reg.is_parameter()) {
           int parameter_index = reg.ToParameterIndex(parameter_count);
           DCHECK_NE(parameter_index, 0);
           os << "a" << parameter_index - 1;
         } else {
           os << "r" << reg.index();
         }
@@ skipping 127 matching lines @@
   }
   if (reg5.is_valid() && reg4.index() + 1 != reg5.index()) {
     return false;
   }
   return true;
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8