Tail call from TurboFan into select runtime calls

src/compiler/js-context-relaxation.cc

 // Copyright 2014 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/frame-states.h"
 #include "src/compiler/js-context-relaxation.h"
 #include "src/compiler/js-operator.h"
 #include "src/compiler/node.h"
 #include "src/compiler/node-properties.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 Reduction JSContextRelaxation::Reduce(Node* node) {
   switch (node->opcode()) {
+    case IrOpcode::kJSCallRuntime: {
+      const CallRuntimeParameters& p = CallRuntimeParametersOf(node->op());
+      const Runtime::Function* fun = Runtime::FunctionForId(p.id());
+      switch (fun->function_id) {
+#define IC_CASE(name, number_of_args, result_size) \
+  case Runtime::k##name:                           \
+    break;
+        FOR_EACH_INTRINSIC_IC(IC_CASE)
+#undef IC_CASE
+        default:
+          return NoChange();
+      }
+    }
+    // Fall through
     case IrOpcode::kJSCallFunction:
     case IrOpcode::kJSToNumber: {
       Node* frame_state = NodeProperties::GetFrameStateInput(node, 0);
       Node* outer_frame = frame_state;
       Node* original_context = NodeProperties::GetContextInput(node);
       Node* candidate_new_context = original_context;
       do {
         FrameStateInfo frame_state_info(
             OpParameter<FrameStateInfo>(outer_frame->op()));
         const FrameStateFunctionInfo* function_info =
@@ skipping 31 matching lines @@
     }
     default:
       break;
   }
   return NoChange();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8