[array] Skip write barrier when sorting packed Smis

R=jgruber@chromium.org

Bug: chromium:873555
Change-Id: I6268bedf47a89194875d1179e603bcfe972c9d68
Reviewed-on: https://chromium-review.googlesource.com/1172282Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Simon Zünd <szuend@google.com>
Cr-Commit-Position: refs/heads/master@{#55077}

src/builtins/base.tq

@@ -63,6 +63,7 @@ type ExtractFixedArrayFlags generates
 type ParameterMode generates 'TNode<Int32T>' constexpr 'ParameterMode';
 type RootListIndex generates 'TNode<Int32T>' constexpr 'Heap::RootListIndex';
 type AllocationFlags generates 'TNode<Int32T>' constexpr 'AllocationFlags';
+type WriteBarrierMode generates 'TNode<Int32T>' constexpr 'WriteBarrierMode';
 
 type MessageTemplate constexpr 'MessageTemplate::Template';
 
@@ -166,6 +167,9 @@ const INTPTR_PARAMETERS: constexpr ParameterMode generates 'INTPTR_PARAMETERS';
 const kAllowLargeObjectAllocation: constexpr AllocationFlags
     generates 'kAllowLargeObjectAllocation';
 
+const SKIP_WRITE_BARRIER: constexpr WriteBarrierMode
+    generates 'SKIP_WRITE_BARRIER';
+
 extern macro Is64(): constexpr bool;
 
 extern macro SelectBooleanConstant(bool): Boolean;
@@ -642,6 +646,9 @@ extern operator
 extern operator
 '[]=' macro StoreFixedArrayElementSmi(FixedArray, Smi, Object): void;
 
+extern macro StoreFixedArrayElementSmi(FixedArray, Smi, Object,
+  constexpr WriteBarrierMode): void;
+
 extern operator '.instance_type' macro LoadMapInstanceType(Map): int32;
 
 extern macro LoadFixedDoubleArrayElement(FixedDoubleArray, Smi): float64;

third_party/v8/builtins/array-sort.tq

@@ -213,7 +213,7 @@ module array {
       context: Context, sortState: FixedArray, elements: HeapObject, index: Smi,
       value: Object): Smi {
     const elems: FixedArray = unsafe_cast<FixedArray>(elements);
-    elems[index] = value;
+    StoreFixedArrayElementSmi(elems, index, value, SKIP_WRITE_BARRIER);
     return kSuccess;
   }