Introduce LiteralsArray to hide it's implementation.

src/arm64/lithium-codegen-arm64.cc

Index: src/arm64/lithium-codegen-arm64.cc
diff --git a/src/arm64/lithium-codegen-arm64.cc b/src/arm64/lithium-codegen-arm64.cc
index 29192756e5d6bd3566f8b03510a5f3543b62a8fc..29858bb7a8358d8e5d0fab5299d4e62e3d38f2db 100644
--- a/src/arm64/lithium-codegen-arm64.cc
+++ b/src/arm64/lithium-codegen-arm64.cc
@@ -5648,7 +5648,7 @@ void LCodeGen::DoRegExpLiteral(LRegExpLiteral* instr) {
   // x0 = regexp literal clone.
   // x10-x12 are used as temporaries.
   int literal_offset =
-      FixedArray::OffsetOfElementAt(instr->hydrogen()->literal_index());
+      LiteralsArray::OffsetOfLiteralAt(instr->hydrogen()->literal_index());
   __ LoadObject(x7, instr->hydrogen()->literals());
   __ Ldr(x1, FieldMemOperand(x7, literal_offset));
   __ JumpIfNotRoot(x1, Heap::kUndefinedValueRootIndex, &materialized);