[turbofan] add configuration parameters for register allocator

src/interface-descriptors.cc

Index: src/interface-descriptors.cc
diff --git a/src/interface-descriptors.cc b/src/interface-descriptors.cc
index d41d53b14fa40d0d3d37ec5a1bca53fb6e726884..b1ebc3faeef53feaf626409c17280e97ebb13941 100644
--- a/src/interface-descriptors.cc
+++ b/src/interface-descriptors.cc
@@ -42,7 +42,7 @@ void CallInterfaceDescriptorData::Initialize(
 }
 
 
-const char* CallInterfaceDescriptor::DebugName(Isolate* isolate) {
+const char* CallInterfaceDescriptor::DebugName(Isolate* isolate) const {
   CallInterfaceDescriptorData* start = isolate->call_descriptor_data(0);
   size_t index = data_ - start;
   DCHECK(index < CallDescriptors::NUMBER_OF_DESCRIPTORS);