Introduce {ConstantElementsPair} struct for type safety.

src/interpreter/bytecode-array-builder.cc

Index: src/interpreter/bytecode-array-builder.cc
diff --git a/src/interpreter/bytecode-array-builder.cc b/src/interpreter/bytecode-array-builder.cc
index d98d48cc780779c52437a9c15af51f1469130a63..39c233d07425d96defcad285243cfd5d73ec263a 100644
--- a/src/interpreter/bytecode-array-builder.cc
+++ b/src/interpreter/bytecode-array-builder.cc
@@ -638,7 +638,8 @@ BytecodeArrayBuilder& BytecodeArrayBuilder::CreateRegExpLiteral(
 }
 
 BytecodeArrayBuilder& BytecodeArrayBuilder::CreateArrayLiteral(
-    Handle<FixedArray> constant_elements, int literal_index, int flags) {
+    Handle<ConstantElementsPair> constant_elements, int literal_index,
+    int flags) {
   size_t constant_elements_entry = GetConstantPoolEntry(constant_elements);
   OutputCreateArrayLiteral(constant_elements_entry, literal_index, flags);
   return *this;