[interpreter] Introduce bytecode generation pipeline.

src/interpreter/bytecode-generator.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/bytecode-generator.h"
 
 #include "src/ast/scopes.h"
 #include "src/code-stubs.h"
 #include "src/compiler.h"
 #include "src/interpreter/bytecode-register-allocator.h"
@@ skipping 637 matching lines @@
                                          size_t size,
                                          ZoneVector<BytecodeLabel>& targets) {
   // TODO(neis): Optimize this by using a proper jump table.
   for (size_t i = start_index; i < start_index + size; i++) {
     DCHECK(0 <= i && i < targets.size());
     builder()
         ->LoadLiteral(Smi::FromInt(static_cast<int>(i)))
         .CompareOperation(Token::Value::EQ_STRICT, index)
         .JumpIfTrue(&(targets[i]));
   }
+  // TODO(oth): This should be an abort via the runtime with a
+  // corresponding message., An illegal bytecode should never be
+  // emitted in valid bytecode.
   builder()->Illegal();  // Should never get here.
 }
 
 void BytecodeGenerator::VisitIterationHeader(IterationStatement* stmt,
                                              LoopBuilder* loop_builder) {
   // Recall that stmt->yield_count() is always zero inside ordinary
   // (i.e. non-generator) functions.
 
   // Collect all labels for generator resume points within the loop (if any) so
   // that they can be bound to the loop header below. Also create fresh labels
@@ skipping 2599 matching lines @@
 }
 
 
 int BytecodeGenerator::feedback_index(FeedbackVectorSlot slot) const {
   return info()->shared_info()->feedback_vector()->GetIndex(slot);
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8