[es6] Perform the IsConstructor test in GetSuperConstructor.

src/compiler/js-operator.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/compiler/js-operator.h"
 
 #include <limits>
 
 #include "src/base/lazy-instance.h"
 #include "src/compiler/opcodes.h"
@@ skipping 435 matching lines @@
   V(Create, Operator::kEliminatable, 2, 1)                  \
   V(CreateIterResultObject, Operator::kEliminatable, 2, 1)  \
   V(HasProperty, Operator::kNoProperties, 2, 1)             \
   V(TypeOf, Operator::kPure, 1, 1)                          \
   V(InstanceOf, Operator::kNoProperties, 2, 1)              \
   V(ForInNext, Operator::kNoProperties, 4, 1)               \
   V(ForInPrepare, Operator::kNoProperties, 1, 3)            \
   V(LoadMessage, Operator::kNoThrow, 0, 1)                  \
   V(StoreMessage, Operator::kNoThrow, 1, 0)                 \
   V(GeneratorRestoreContinuation, Operator::kNoThrow, 1, 1) \
-  V(StackCheck, Operator::kNoWrite, 0, 0)
+  V(StackCheck, Operator::kNoWrite, 0, 0)                   \
+  V(GetSuperConstructor, Operator::kNoProperties, 1, 1)

[Benedikt Meurer, 2016/11/23 04:51:00]

This should be marked as Operator::kNoWrite.

[Henrique Ferreiro, 2016/12/01 12:22:22]

Would you mind explaining what would be the difference with ToName and similar
operators which use kNoProperties? I would assume they work in the same way.

[Benedikt Meurer, 2016/12/01 13:11:51]

ToName can call into arbitrary JavaScript (via ToPrimitive conversions). But
GetSuperConstructor will never execute arbitrary JavaScript, so it has no
observable side effects (which is expressed by kNoWrite, yeah I know the name
sucks).

 
 #define BINARY_OP_LIST(V) \
   V(BitwiseOr)            \
   V(BitwiseXor)           \
   V(BitwiseAnd)           \
   V(ShiftLeft)            \
   V(ShiftRight)           \
   V(ShiftRightLogical)    \
   V(Add)                  \
   V(Subtract)             \
@@ skipping 410 matching lines @@
   return new (zone()) Operator1<Handle<ScopeInfo>>(               // --
       IrOpcode::kJSCreateScriptContext, Operator::kNoProperties,  // opcode
       "JSCreateScriptContext",                                    // name
       1, 1, 1, 1, 1, 2,                                           // counts
       scpope_info);                                               // parameter
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8