[turbofan] Implement the call protocol properly for direct calls.

src/compiler/linkage.h

Index: src/compiler/linkage.h
diff --git a/src/compiler/linkage.h b/src/compiler/linkage.h
index e01ff61002e10682fb2018c7a7b787e3ea4804a5..0f4b8db1c448055bc4568d5673bbf0b26a53fce5 100644
--- a/src/compiler/linkage.h
+++ b/src/compiler/linkage.h
@@ -258,7 +258,7 @@ std::ostream& operator<<(std::ostream& os, const CallDescriptor::Kind& k);
 //
 //                  #0          #1     #2     #3     [...]             #n
 // Call[CodeStub]   code,       arg 1, arg 2, arg 3, [...],            context
-// Call[JSFunction] function,   rcvr,  arg 1, arg 2, [...],            context
+// Call[JSFunction] function,   rcvr,  arg 1, arg 2, [...],      #arg, context
 // Call[Runtime]    CEntryStub, arg 1, arg 2, arg 3, [...], fun, #arg, context
 class Linkage : public ZoneObject {
  public: