[ignition] desugar GetIterator() via bytecode rather than via AST

test/unittests/interpreter/bytecode-array-builder-unittest.cc

 // Copyright 2014 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/interpreter/bytecode-array-builder.h"
 #include "src/interpreter/bytecode-array-iterator.h"
 #include "src/interpreter/bytecode-label.h"
 #include "src/interpreter/bytecode-register-allocator.h"
@@ skipping 184 matching lines @@
       .CompareOperation(Token::Value::INSTANCEOF, reg, 8)
       .CompareOperation(Token::Value::IN, reg, 9);
 
   // Emit conversion operator invocations.
   builder.ConvertAccumulatorToNumber(reg)
       .ConvertAccumulatorToObject(reg)
       .ConvertAccumulatorToName(reg);
 
   // Short jumps with Imm8 operands
   {
-    BytecodeLabel start, after_jump1, after_jump2, after_jump3, after_jump4;
+    BytecodeLabel start, after_jump1, after_jump2, after_jump3, after_jump4,
+        after_jump5;
     builder.Bind(&start)
         .Jump(&after_jump1)
         .Bind(&after_jump1)
         .JumpIfNull(&after_jump2)
         .Bind(&after_jump2)
         .JumpIfUndefined(&after_jump3)
         .Bind(&after_jump3)
         .JumpIfNotHole(&after_jump4)
         .Bind(&after_jump4)
+        .JumpIfJSReceiver(&after_jump5)
+        .Bind(&after_jump5)
         .JumpLoop(&start, 0);
   }
 
   // Longer jumps with constant operands
-  BytecodeLabel end[8];
+  BytecodeLabel end[9];
   {
     BytecodeLabel after_jump;
     builder.Jump(&end[0])
         .Bind(&after_jump)
         .LoadTrue()
         .JumpIfTrue(&end[1])
         .LoadTrue()
         .JumpIfFalse(&end[2])
         .LoadLiteral(Smi::kZero)
         .JumpIfTrue(&end[3])
         .LoadLiteral(Smi::kZero)
         .JumpIfFalse(&end[4])
         .JumpIfNull(&end[5])
         .JumpIfUndefined(&end[6])
-        .JumpIfNotHole(&end[7]);
+        .JumpIfNotHole(&end[7])
+        .LoadLiteral(factory->prototype_string())

[rmcilroy, 2016/12/06 15:02:28]

nit - no need to load the literal here (the code in this test is never executed
so doesn't need to make sense :).

[caitp, 2016/12/06 15:14:58]

Acknowledged.

+        .JumpIfJSReceiver(&end[8]);
   }
 
   // Perform an operation that returns boolean value to
   // generate JumpIfTrue/False
   {
     BytecodeLabel after_jump1, after_jump2;
     builder.CompareOperation(Token::Value::EQ, reg, 1)
         .JumpIfTrue(&after_jump1)
         .Bind(&after_jump1)
         .CompareOperation(Token::Value::EQ, reg, 2)
@@ skipping 485 matching lines @@
     iterator.Advance();
   }
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kReturn);
   iterator.Advance();
   CHECK(iterator.done());
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8