[Interpreter] Make ForInPrepare take a kRegTriple8 and ForInNext take kRegPair8 for cache state

src/interpreter/bytecode-generator.cc

Index: src/interpreter/bytecode-generator.cc
diff --git a/src/interpreter/bytecode-generator.cc b/src/interpreter/bytecode-generator.cc
index 10c78ffc4984518e5b8cafa0a0d64cdc05095e21..37d33a736be118b65e4192247985f2c0e10df9a3 100644
--- a/src/interpreter/bytecode-generator.cc
+++ b/src/interpreter/bytecode-generator.cc
@@ -894,10 +894,12 @@ void BytecodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   builder()->CastAccumulatorToJSObject();
   builder()->JumpIfNull(&not_object_label);
   builder()->StoreAccumulatorInRegister(receiver);
-  Register cache_type = execution_result()->NewRegister();
-  Register cache_array = execution_result()->NewRegister();
-  Register cache_length = execution_result()->NewRegister();
-  builder()->ForInPrepare(cache_type, cache_array, cache_length);
+
+  execution_result()->PrepareForConsecutiveAllocations(3);
+  Register cache_type = execution_result()->NextConsecutiveRegister();
+  Register cache_array = execution_result()->NextConsecutiveRegister();
+  Register cache_length = execution_result()->NextConsecutiveRegister();
+  builder()->ForInPrepare(cache_type);
 
   // Set up loop counter
   Register index = execution_result()->NewRegister();
@@ -909,7 +911,8 @@ void BytecodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   loop_builder.Condition();
   builder()->ForInDone(index, cache_length);
   loop_builder.BreakIfTrue();
-  builder()->ForInNext(receiver, cache_type, cache_array, index);
+  DCHECK(Register::AreContiguous(cache_type, cache_array));
+  builder()->ForInNext(receiver, index, cache_type);
   loop_builder.ContinueIfUndefined();
   VisitForInAssignment(stmt->each(), stmt->EachFeedbackSlot());
   Visit(stmt->body());