Remove some dead fields from isolate.h

src/s390/code-stubs-s390.cc

 // Copyright 2014 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.
 
 #if V8_TARGET_ARCH_S390
 
 #include "src/code-stubs.h"
 #include "src/api-arguments.h"
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
@@ skipping 821 matching lines @@
 
 void RestoreRegistersStateStub::GenerateAheadOfTime(Isolate* isolate) {
   RestoreRegistersStateStub stub(isolate);
   stub.GetCode();
 }
 
 void CodeStub::GenerateFPStubs(Isolate* isolate) {
   SaveFPRegsMode mode = kSaveFPRegs;
   CEntryStub(isolate, 1, mode).GetCode();
   StoreBufferOverflowStub(isolate, mode).GetCode();
-  isolate->set_fp_stubs_generated(true);
 }
 
 void CEntryStub::GenerateAheadOfTime(Isolate* isolate) {
   CEntryStub stub(isolate, 1, kDontSaveFPRegs);
   stub.GetCode();
 }
 
 void CEntryStub::Generate(MacroAssembler* masm) {
   // Called from JavaScript; parameters are on stack as if calling JS function.
   // r2: number of arguments including receiver
@@ skipping 3421 matching lines @@
   CallApiFunctionAndReturn(masm, api_function_address, thunk_ref,
                            kStackUnwindSpace, NULL, return_value_operand, NULL);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_S390