[turbofan] Remove access to FunctionType from call interface.

src/builtins/builtins.cc

Index: src/builtins/builtins.cc
diff --git a/src/builtins/builtins.cc b/src/builtins/builtins.cc
index 740842404bf6622f8ff9153eb3127bd655ed5f7b..2ab234fc70781e1f8fee7d5750535c363bd95094 100644
--- a/src/builtins/builtins.cc
+++ b/src/builtins/builtins.cc
@@ -102,7 +102,7 @@ Code* BuildWithCodeStubAssemblerCS(Isolate* isolate,
   // and this construction just queries the details from the descriptors table.
   CallInterfaceDescriptor descriptor(isolate, interface_descriptor);
   // Ensure descriptor is already initialized.
-  DCHECK_NOT_NULL(descriptor.GetFunctionType());
+  DCHECK_LE(0, descriptor.GetRegisterParameterCount());
   CodeStubAssembler assembler(isolate, &zone, descriptor, flags, name);
   generator(&assembler);
   Handle<Code> code = assembler.GenerateCode();