Introduce TypeFeedbackVector, as FixedArray grew constrictive.

src/compiler.h

 // Copyright 2012 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.
 
 #ifndef V8_COMPILER_H_
 #define V8_COMPILER_H_
 
 #include "src/allocation.h"
 #include "src/ast.h"
 #include "src/zone.h"
@@ skipping 208 matching lines @@
 
   void SetFunction(FunctionLiteral* literal) {
     DCHECK(function_ == NULL);
     function_ = literal;
   }
   void PrepareForCompilation(Scope* scope);
   void SetGlobalScope(Scope* global_scope) {
     DCHECK(global_scope_ == NULL);
     global_scope_ = global_scope;
   }
-  Handle<FixedArray> feedback_vector() const {
+  Handle<TypeFeedbackVector> feedback_vector() const {
     return feedback_vector_;
   }
   void SetCode(Handle<Code> code) { code_ = code; }
   void SetExtension(v8::Extension* extension) {
     DCHECK(!is_lazy());
     extension_ = extension;
   }
   void SetCachedData(ScriptData** cached_data,
                      ScriptCompiler::CompileOptions compile_options) {
     compile_options_ = compile_options;
@@ skipping 204 matching lines @@
   // Fields possibly needed for eager compilation, NULL by default.
   v8::Extension* extension_;
   ScriptData** cached_data_;
   ScriptCompiler::CompileOptions compile_options_;
 
   // The context of the caller for eval code, and the global context for a
   // global script. Will be a null handle otherwise.
   Handle<Context> context_;
 
   // Used by codegen, ultimately kept rooted by the SharedFunctionInfo.
-  Handle<FixedArray> feedback_vector_;
+  Handle<TypeFeedbackVector> feedback_vector_;
 
   // Compilation mode flag and whether deoptimization is allowed.
   Mode mode_;
   BailoutId osr_ast_id_;
   // The unoptimized code we patched for OSR may not be the shared code
   // afterwards, since we may need to compile it again to include deoptimization
   // data.  Keep track which code we patched.
   Handle<Code> unoptimized_code_;
 
   // Flag whether compilation needs to be aborted due to dependency change.
@@ skipping 272 matching lines @@
   Zone zone_;
   unsigned info_zone_start_allocation_size_;
   base::ElapsedTimer timer_;
 
   DISALLOW_COPY_AND_ASSIGN(CompilationPhase);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_COMPILER_H_