Load from PropertyCells using PropertyCell::kValueOffset rather than Cell::kValueOffset

BUG=

Review URL: https://codereview.chromium.org/1019563002

Cr-Commit-Position: refs/heads/master@{#27280}

src/ic/arm/handler-compiler-arm.cc

@@ -728,7 +728,7 @@ Handle<Code> NamedLoadHandlerCompiler::CompileLoadGlobal(
   Register result = StoreDescriptor::ValueRegister();
   Handle<WeakCell> weak_cell = factory()->NewWeakCell(cell);
   __ LoadWeakValue(result, weak_cell, &miss);
-  __ ldr(result, FieldMemOperand(result, Cell::kValueOffset));
+  __ ldr(result, FieldMemOperand(result, PropertyCell::kValueOffset));
 
   // Check for deleted property if property can actually be deleted.
   if (is_configurable) {

src/ic/arm64/handler-compiler-arm64.cc

@@ -345,7 +345,7 @@ Handle<Code> NamedLoadHandlerCompiler::CompileLoadGlobal(
   Register result = StoreDescriptor::ValueRegister();
   Handle<WeakCell> weak_cell = factory()->NewWeakCell(cell);
   __ LoadWeakValue(result, weak_cell, &miss);
-  __ Ldr(result, FieldMemOperand(result, Cell::kValueOffset));
+  __ Ldr(result, FieldMemOperand(result, PropertyCell::kValueOffset));
 
   // Check for deleted property if property can actually be deleted.
   if (is_configurable) {

src/ic/x64/handler-compiler-x64.cc

@@ -209,7 +209,8 @@ void PropertyHandlerCompiler::GenerateCheckPropertyCell(
   Factory* factory = masm->isolate()->factory();
   Handle<WeakCell> weak_cell = factory->NewWeakCell(cell);
   __ LoadWeakValue(scratch, weak_cell, miss);
-  __ Cmp(FieldOperand(scratch, Cell::kValueOffset), factory->the_hole_value());
+  __ Cmp(FieldOperand(scratch, PropertyCell::kValueOffset),
+         factory->the_hole_value());
   __ j(not_equal, miss);
 }