[explicit isolates] Fix up src/elements.cc

Pipe through Isolate into several elements.cc functions, to avoid using
HeapObject::GetIsolate. In some cases, uses ReadOnlyObject::GetIsolate
which is allowed.

(Autogenerated using Leszek's clang-bubble-getisolate)

Bug: v8:7786
Change-Id: Idcbfaadf95c3c2b96d03b606da5594774bac2f7e
Reviewed-on: https://chromium-review.googlesource.com/1107706Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53932}

src/ast/ast.cc

@@ -633,7 +633,8 @@ void ArrayLiteral::BuildConstantElements(Isolate* isolate) {
     elements = isolate->factory()->NewFixedDoubleArray(constants_length);
     // We are copying from non-fast-double to fast-double.
     ElementsKind from_kind = TERMINAL_FAST_ELEMENTS_KIND;
-    accessor->CopyElements(fixed_array, from_kind, elements, constants_length);
+    accessor->CopyElements(isolate, fixed_array, from_kind, elements,
+                           constants_length);
   }
 
   // Remember both the literal's constant values as well as the ElementsKind.

src/elements.h

@@ -180,7 +180,7 @@ class ElementsAccessor {
 
   virtual void Reverse(JSObject* receiver) = 0;
 
-  virtual void CopyElements(Handle<FixedArrayBase> source,
+  virtual void CopyElements(Isolate* isolate, Handle<FixedArrayBase> source,
                             ElementsKind source_kind,
                             Handle<FixedArrayBase> destination, int size) = 0;