Remove FLAG_flush_optimized_code_cache

It's no longer necessary, and has been off for a year.

BUG=

Review-Url: https://codereview.chromium.org/2553643002
Cr-Commit-Position: refs/heads/master@{#41499}

src/heap/objects-visiting-inl.h

@@ -429,12 +429,6 @@ void StaticMarkingVisitor<StaticVisitor>::VisitSharedFunctionInfo(
   if (shared->ic_age() != heap->global_ic_age()) {
     shared->ResetForNewContext(heap->global_ic_age());
   }
-  if (FLAG_flush_optimized_code_cache) {
-    if (!shared->OptimizedCodeMapIsCleared()) {
-      // Always flush the optimized code map if requested by flag.
-      shared->ClearOptimizedCodeMap();
-    }
-  }
   MarkCompactCollector* collector = heap->mark_compact_collector();
   if (collector->is_code_flushing_enabled()) {
     if (IsFlushable(heap, shared)) {

test/cctest/heap/test-heap.cc

@@ -4260,7 +4260,6 @@ TEST(Regress169928) {
 
 #ifdef DEBUG
 TEST(Regress513507) {
-  i::FLAG_flush_optimized_code_cache = false;
   i::FLAG_allow_natives_syntax = true;
   i::FLAG_gc_global = true;
   CcTest::InitializeVM();
@@ -4317,7 +4316,6 @@ TEST(Regress513507) {
 
 TEST(Regress514122) {
   if (!i::FLAG_incremental_marking) return;
-  i::FLAG_flush_optimized_code_cache = false;
   i::FLAG_allow_natives_syntax = true;
   CcTest::InitializeVM();
   Isolate* isolate = CcTest::i_isolate();
@@ -4410,7 +4408,6 @@ TEST(Regress514122) {
 
 
 TEST(OptimizedCodeMapReuseEntries) {
-  i::FLAG_flush_optimized_code_cache = false;
   i::FLAG_allow_natives_syntax = true;
   // BUG(v8:4598): Since TurboFan doesn't treat maps in code weakly, we can't
   // run this test.
@@ -4518,7 +4515,6 @@ TEST(OptimizedCodeMapReuseEntries) {
 
 
 TEST(Regress513496) {
-  i::FLAG_flush_optimized_code_cache = false;
   i::FLAG_allow_natives_syntax = true;
   CcTest::InitializeVM();
   Isolate* isolate = CcTest::i_isolate();

test/mjsunit/regress/regress-crbug-513507.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --noflush-optimized-code-cache --allow-natives-syntax
+// Flags: --allow-natives-syntax
 
 // The following triggers a GC in SharedFunctionInfo::AddToOptimizedCodeMap.
 // Flags: --gc-interval=1234 --gc-global