[Interpreter] Add support for loading literals from the constant pool.

src/interpreter/interpreter.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/interpreter/interpreter.h"
 
 #include "src/compiler.h"
 #include "src/compiler/interpreter-assembler.h"
 #include "src/factory.h"
 #include "src/interpreter/bytecode-generator.h"
@@ skipping 88 matching lines @@
 //
 // Load an 8-bit integer literal into the accumulator as a Smi.
 void Interpreter::DoLdaSmi8(compiler::InterpreterAssembler* assembler) {
   Node* raw_int = __ BytecodeOperandImm8(0);
   Node* smi_int = __ SmiTag(raw_int);
   __ SetAccumulator(smi_int);
   __ Dispatch();
 }
 
 
+// LdaConstant <idx>
+//
+// Load constant literal at |idx| in the constant pool into the accumulator.
+void Interpreter::DoLdaConstant(compiler::InterpreterAssembler* assembler) {
+  Node* index = __ BytecodeOperandIdx(0);
+  Node* constant = __ LoadConstantPoolEntry(index);
+  __ SetAccumulator(constant);
+  __ Dispatch();
+}
+
+
 // LdaUndefined
 //
 // Load Undefined into the accumulator.
 void Interpreter::DoLdaUndefined(compiler::InterpreterAssembler* assembler) {
   Node* undefined_value = __ HeapConstant(Unique<HeapObject>::CreateImmovable(
       isolate_->factory()->undefined_value()));
   __ SetAccumulator(undefined_value);
   __ Dispatch();
 }
 
@@ skipping 121 matching lines @@
 //
 // Return the value in register 0.
 void Interpreter::DoReturn(compiler::InterpreterAssembler* assembler) {
   __ Return();
 }
 
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8