[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 92d1b92e85bc798b1972bebdab9544b38a637282..8d6a2fb5a77f813ca9c1845331ad97975a413ade 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();
@@ -260,6 +261,11 @@ class BytecodeArrayBuilder final : public ZoneObject {
   // entry, so that it can be referenced by above exception handling support.
   int NewHandlerEntry() { return handler_table_builder()->NewHandlerEntry(); }
 
+  // Allocates a slot in the constant pool which can later be inserted.
+  size_t AllocateConstantPoolEntry();
+  // Inserts a entry into an allocated constant pool entry.
+  void InsertConstantPoolEntryAt(size_t entry, Handle<Object> object);
+
   void InitializeReturnPosition(FunctionLiteral* literal);
 
   void SetStatementPosition(Statement* stmt);