[turbofan] Add support for accessor inlining.

src/compiler.h

Index: src/compiler.h
diff --git a/src/compiler.h b/src/compiler.h
index bda645d37333911abc39d7cb0602b40a80027562..5eab5033853be04ce9f6282a80862861e1942379 100644
--- a/src/compiler.h
+++ b/src/compiler.h
@@ -162,6 +162,7 @@ class CompilationInfo final {
     kBailoutOnUninitialized = 1 << 16,
     kOptimizeFromBytecode = 1 << 17,
     kTypeFeedbackEnabled = 1 << 18,
+    kAccessorInliningEnabled = 1 << 19,
   };
 
   CompilationInfo(ParseInfo* parse_info, Handle<JSFunction> closure);
@@ -278,6 +279,12 @@ class CompilationInfo final {
     return GetFlag(kTypeFeedbackEnabled);
   }
 
+  void MarkAsAccessorInliningEnabled() { SetFlag(kAccessorInliningEnabled); }
+
+  bool is_accessor_inlining_enabled() const {
+    return GetFlag(kAccessorInliningEnabled);
+  }
+
   void MarkAsSourcePositionsEnabled() { SetFlag(kSourcePositionsEnabled); }
 
   bool is_source_positions_enabled() const {