Revert of Refactor SharedFunctionInfo::IsBuiltin.

src/compiler/js-inlining-heuristic.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/compiler/js-inlining-heuristic.h"
 
 #include "src/compilation-info.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/simplified-operator.h"
@@ skipping 28 matching lines @@
     }
     return value_input_count;
   }
   return 0;
 }
 
 bool CanInlineFunction(Handle<JSFunction> function) {
   // Built-in functions are handled by the JSBuiltinReducer.
   if (function->shared()->HasBuiltinFunctionId()) return false;
 
-  // Only choose user code for inlining.
-  if (!function->shared()->IsUserJavaScript()) return false;
+  // Don't inline builtins.
+  if (function->shared()->IsBuiltin()) return false;
 
   // Quick check on the size of the AST to avoid parsing large candidate.
   if (function->shared()->ast_node_count() > FLAG_max_inlined_nodes) {
     return false;
   }
 
   // Avoid inlining across the boundary of asm.js code.
   if (function->shared()->asm_function()) return false;
   return true;
 }
@@ skipping 233 matching lines @@
   return jsgraph()->common();
 }
 
 SimplifiedOperatorBuilder* JSInliningHeuristic::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8