Initial shot at deoptimizing JSCallFunction in Turbofan.

src/compiler/linkage-impl.h

Index: src/compiler/linkage-impl.h
diff --git a/src/compiler/linkage-impl.h b/src/compiler/linkage-impl.h
index 212a622ac082e475db1befcf991896ce68778eb2..36939cc6cc514167cba02e17a88af74b3cbc0d7c 100644
--- a/src/compiler/linkage-impl.h
+++ b/src/compiler/linkage-impl.h
@@ -128,7 +128,8 @@ class LinkageHelper {
   template <typename LinkageTraits>
   static CallDescriptor* GetStubCallDescriptor(
       Zone* zone, CodeStubInterfaceDescriptor* descriptor,
-      int stack_parameter_count) {
+      int stack_parameter_count,
+      CallDescriptor::DeoptimizationSupport can_deoptimize) {
     int register_parameter_count = descriptor->GetEnvironmentParameterCount();
     int parameter_count = register_parameter_count + stack_parameter_count;
     const int code_count = 1;
@@ -165,9 +166,8 @@ class LinkageHelper {
                        locations,                        // locations
                        Operator::kNoProperties,          // properties
                        kNoCalleeSaved,  // callee-saved registers
-                       CallDescriptor::kCannotDeoptimize,  // deoptimization
+                       can_deoptimize,  // deoptimization
                        CodeStub::MajorName(descriptor->MajorKey(), false));
-    // TODO(jarin) should deoptimize!
   }