[Interpreter] Avoid allocating pairs array in VisitDeclarations.

src/interpreter/bytecode-array-builder.h

Index: src/interpreter/bytecode-array-builder.h
diff --git a/src/interpreter/bytecode-array-builder.h b/src/interpreter/bytecode-array-builder.h
index ca62ba6b6794f8ec826fb60858605cbd317107ca..a17f679c63a9d6c8898fcf2838101f37e16b2110 100644
--- a/src/interpreter/bytecode-array-builder.h
+++ b/src/interpreter/bytecode-array-builder.h
@@ -79,6 +79,7 @@ class BytecodeArrayBuilder final : public ZoneObject {
   bool TemporaryRegisterIsLive(Register reg) const;
 
   // Constant loads to accumulator.
+  BytecodeArrayBuilder& LoadConstantPoolEntry(size_t entry);
   BytecodeArrayBuilder& LoadLiteral(v8::internal::Smi* value);
   BytecodeArrayBuilder& LoadLiteral(Handle<Object> object);
   BytecodeArrayBuilder& LoadUndefined();
@@ -258,6 +259,11 @@ class BytecodeArrayBuilder final : public ZoneObject {
   // entry, so that it can be referenced by above exception handling support.
   int NewHandlerEntry() { return handler_table_builder()->NewHandlerEntry(); }
 
+  // Reserves a slot in the constant pool which can later be inserted.
+  size_t ReserveConstantPoolEntry();
+  // Inserts a entry into a reserved constant pool entry.
+  void InsertReservedConstantPoolEntry(size_t entry, Handle<Object> object);
+
   void InitializeReturnPosition(FunctionLiteral* literal);
 
   void SetStatementPosition(Statement* stmt);