[turbofan] Correctify lowering of Uint8ClampedArray buffer access.

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"
@@ skipping 763 matching lines @@
   HeapObjectMatcher<Object> mbase(base);
   if (mbase.HasValue() && mbase.Value().handle()->IsJSTypedArray()) {
     Handle<JSTypedArray> const array =
         Handle<JSTypedArray>::cast(mbase.Value().handle());
     array->GetBuffer()->set_is_neuterable(false);
     BufferAccess const access(array->type());
     size_t const k = ElementSizeLog2Of(access.machine_type());
     double const byte_length = array->byte_length()->Number();
     CHECK_LT(k, arraysize(shifted_int32_ranges_));
     if (IsExternalArrayElementsKind(array->map()->elements_kind()) &&
-        access.external_array_type() != kExternalUint8ClampedArray &&
         key_type->Is(shifted_int32_ranges_[k]) && byte_length <= kMaxInt) {
       // JSLoadProperty(typed-array, int32)
       Handle<ExternalArray> elements =
           Handle<ExternalArray>::cast(handle(array->elements()));
       Node* buffer = jsgraph()->PointerConstant(elements->external_pointer());
       Node* length = jsgraph()->Constant(byte_length);
       Node* effect = NodeProperties::GetEffectInput(node);
       Node* control = NodeProperties::GetControlInput(node);
       // Check if we can avoid the bounds check.
       if (key_type->Min() >= 0 && key_type->Max() < array->length()->Number()) {
@@ skipping 282 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSTypedLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8