Make FastNewFunctionContextStub take slots parameter

src/code-stubs.h

 // Copyright 2012 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.
 
 #ifndef V8_CODE_STUBS_H_
 #define V8_CODE_STUBS_H_
 
 #include "src/allocation.h"
 #include "src/assembler.h"
 #include "src/code-stub-assembler.h"
@@ skipping 1040 matching lines @@
   static compiler::Node* Generate(CodeStubAssembler* assembler,
                                   compiler::Node* shared_info,
                                   compiler::Node* context);
 
   DEFINE_CALL_INTERFACE_DESCRIPTOR(FastNewClosure);
   DEFINE_TURBOFAN_CODE_STUB(FastNewClosure, TurboFanCodeStub);
 };
 
 class FastNewFunctionContextStub final : public TurboFanCodeStub {
  public:
   static const int kMaximumSlots = 64;

[klaasb, 2016/07/26 17:04:52]

I'm unsure whether/why we need to still limit this?
From here:
https://chromium.googlesource.com/v8/v8/+/013860d42efb102403207f9a1d9688509d3...
I can see that the original motivation was to limit the amount of code stubs but
with this change there will ever be only one. Get rid of it and all related
lines that branch on it and otherwise call the runtime?

[rmcilroy, 2016/07/27 11:11:39]

Sounds reasonable to me, any reason why not to do this Benedikt?

[Benedikt Meurer, 2016/08/01 17:35:08]

Makes sense. Please do that.

 
-  FastNewFunctionContextStub(Isolate* isolate, int slots)
-      : TurboFanCodeStub(isolate) {
-    DCHECK(slots >= 0 && slots <= kMaximumSlots);
-    minor_key_ = SlotsBits::encode(slots);
-  }
-
-  int slots() const { return SlotsBits::decode(minor_key_); }
+  explicit FastNewFunctionContextStub(Isolate* isolate)
+      : TurboFanCodeStub(isolate) {}
 
  private:
   class SlotsBits : public BitField<int, 0, 8> {};

[rmcilroy, 2016/07/27 11:11:38]

You can delete the SlotBits class now too. 

[klaasb, 2016/07/27 17:06:31]

Done.

 
   DEFINE_CALL_INTERFACE_DESCRIPTOR(FastNewFunctionContext);
   DEFINE_TURBOFAN_CODE_STUB(FastNewFunctionContext, TurboFanCodeStub);
 };
 
 
 class FastNewObjectStub final : public PlatformCodeStub {
  public:
   explicit FastNewObjectStub(Isolate* isolate) : PlatformCodeStub(isolate) {}
 
@@ skipping 2028 matching lines @@
 #undef DEFINE_HYDROGEN_CODE_STUB
 #undef DEFINE_CODE_STUB
 #undef DEFINE_CODE_STUB_BASE
 
 extern Representation RepresentationFromType(Type* type);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CODE_STUBS_H_