Revert of [turbofan] Relax effects and context for JSToNumber(x:plain-primitive).

src/compiler/js-typed-lowering.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/access-builder.h"
 #include "src/compiler/graph-inl.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/js-typed-lowering.h"
 #include "src/compiler/node-aux-data-inl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties-inl.h"
 #include "src/types.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // TODO(turbofan): js-typed-lowering improvements possible
 // - immediately put in type bounds for all new nodes
 // - relax effects from generic but not-side-effecting operations
+// - relax effects for ToNumber(mixed)
 
 
 // Relax the effects of {node} by immediately replacing effect uses of {node}
 // with the effect input to {node}.
 // TODO(turbofan): replace the effect input to {node} with {graph->start()}.
 // TODO(titzer): move into a GraphEditor?
 static void RelaxEffects(Node* node) {
   NodeProperties::ReplaceWithValue(node, node, NULL);
 }
 
@@ skipping 692 matching lines @@
           // to simply reuse the context of the {node}. However, ToNumber()
           // does not require a context anyways, so it's safe to discard it
           // here and pass the dummy context.
           value = graph()->NewNode(javascript()->ToNumber(), value,
                                    jsgraph()->NoContextConstant(),
                                    graph()->start(), graph()->start());
         }
         node->ReplaceInput(i, value);
       }
       node->TrimInputCount(input_count);
-    } else {
-      // JSToNumber(x:plain-primitive,context) => JSToNumber(x,no-context)
-      node->ReplaceInput(1, jsgraph()->NoContextConstant());
     }
     return Changed(node);
   }
   return NoChange();
 }
 
 
 Reduction JSTypedLowering::ReduceJSToStringInput(Node* input) {
   if (input->opcode() == IrOpcode::kJSToString) {
     // Recursively try to reduce the input first.
@@ skipping 293 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSTypedLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8