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

src/interpreter/bytecodes.h

Index: src/interpreter/bytecodes.h
diff --git a/src/interpreter/bytecodes.h b/src/interpreter/bytecodes.h
index 3af68091fe2983af79bc603d1da96610f0b4341c..8af20f7e6d0d0c9978ddbe95b19c3708ea58c1d5 100644
--- a/src/interpreter/bytecodes.h
+++ b/src/interpreter/bytecodes.h
@@ -27,6 +27,7 @@ namespace interpreter {
   V(Idx8, OperandSize::kByte)      \
   V(MaybeReg8, OperandSize::kByte) \
   V(Reg8, OperandSize::kByte)      \
+  V(RegPair8, OperandSize::kByte)  \
                                    \
   /* Short operands. */            \
   V(Count16, OperandSize::kShort)  \
@@ -145,6 +146,8 @@ namespace interpreter {
     OperandType::kIdx16)                                                       \
   V(CallRuntime, OperandType::kIdx16, OperandType::kMaybeReg8,                 \
     OperandType::kCount8)                                                      \
+  V(CallRuntimeForPair, OperandType::kIdx16, OperandType::kMaybeReg8,          \
+    OperandType::kCount8, OperandType::kRegPair8)                              \
   V(CallJSRuntime, OperandType::kIdx16, OperandType::kReg8,                    \
     OperandType::kCount8)                                                      \
                                                                                \