[builtins] Remove some (now) unused code from C++ builtin adaptor.

src/mips64/builtins-mips64.cc

Index: src/mips64/builtins-mips64.cc
diff --git a/src/mips64/builtins-mips64.cc b/src/mips64/builtins-mips64.cc
index 6c8d22498f537ccd38bfc6edf273006f7cc3d1fa..5580acfcc1e2cad4f09ace373b86e767de18706b 100644
--- a/src/mips64/builtins-mips64.cc
+++ b/src/mips64/builtins-mips64.cc
@@ -32,13 +32,6 @@ void Builtins::Generate_Adaptor(MacroAssembler* masm,
   // -----------------------------------
   __ AssertFunction(a1);
 
-  // Make sure we operate in the context of the called function (for example
-  // ConstructStubs implemented in C++ will be run in the context of the caller
-  // instead of the callee, due to the way that [[Construct]] is defined for
-  // ordinary functions).
-  // TODO(bmeurer): Can we make this more robust?
-  __ ld(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
-
   // Insert extra arguments.
   int num_extra_args = 0;
   if (extra_args == NEEDS_CALLED_FUNCTION) {
@@ -49,20 +42,8 @@ void Builtins::Generate_Adaptor(MacroAssembler* masm,
   }
 
   // JumpToExternalReference expects a0 to contain the number of arguments
-  // including the receiver and the extra arguments.  But a0 is only valid
-  // if the called function is marked as DontAdaptArguments, otherwise we
-  // need to load the argument count from the SharedFunctionInfo.
-  Label argc, done_argc;
-  __ ld(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
-  __ lw(a2,
-        FieldMemOperand(a2, SharedFunctionInfo::kFormalParameterCountOffset));
-  __ Branch(&argc, eq, a2,
-            Operand(SharedFunctionInfo::kDontAdaptArgumentsSentinel));
-  __ Daddu(a0, a2, num_extra_args + 1);
-  __ jmp(&done_argc);
-  __ bind(&argc);
+  // including the receiver and the extra arguments.
   __ Daddu(a0, a0, num_extra_args + 1);
-  __ bind(&done_argc);
 
   __ JumpToExternalReference(ExternalReference(id, masm->isolate()));
 }