Add a MathFloor stub generated with TurboFan

src/compiler/access-builder.h

Index: src/compiler/access-builder.h
diff --git a/src/compiler/access-builder.h b/src/compiler/access-builder.h
index 3939f83026c2318be9b19b76f5c99c1fad2d56e8..26fe814652cfc9077b42c3618938437ceaace831 100644
--- a/src/compiler/access-builder.h
+++ b/src/compiler/access-builder.h
@@ -65,6 +65,12 @@ class AccessBuilder final : public AllStatic {
   // Provides access to the charaters of sequential strings.
   static ElementAccess ForSeqStringChar(String::Encoding encoding);
 
+  // Provides access to the SharedFunctionInfo in a JSFunction.
+  static FieldAccess ForJSFunctionSharedFunctionInfo();
+
+  // Provides access to the TypeFeedbackVector in SharedFunctionInfo.
+  static FieldAccess ForSharedFunctionInfoTypeFeedbackVector();
+
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(AccessBuilder);
 };