[compiler] Prepare for partially shipping Ignition.

This prepares the code-base so that Ignition can be enabled on a certain
subset of compilations without setting the {FLAG_ignition} flag (which
enables Ignition on all compilations). We should not check the flag in
question explicitly anywhere outside of the compiler heuristics.

R=mvstanton@chromium.org

Review-Url: https://codereview.chromium.org/2443573002
Cr-Commit-Position: refs/heads/master@{#40617}

src/bootstrapper.cc

@@ -4054,7 +4054,7 @@ bool Genesis::InstallExtensions(Handle<Context> native_context,
           InstallExtension(isolate, "v8/statistics", &extension_states)) &&
          (!FLAG_expose_trigger_failure ||
           InstallExtension(isolate, "v8/trigger-failure", &extension_states)) &&
-         (!(FLAG_ignition && FLAG_trace_ignition_dispatches) ||
+         (!FLAG_trace_ignition_dispatches ||
           InstallExtension(isolate, "v8/ignition-statistics",
                            &extension_states)) &&
          InstallRequestedExtensions(isolate, extensions, &extension_states);

src/d8.cc

@@ -2922,7 +2922,7 @@ int Shell::Main(int argc, char* argv[]) {
       RunShell(isolate);
     }
 
-    if (i::FLAG_ignition && i::FLAG_trace_ignition_dispatches &&
+    if (i::FLAG_trace_ignition_dispatches &&
         i::FLAG_trace_ignition_dispatches_output_file != nullptr) {
       WriteIgnitionDispatchCountersFile(isolate);
     }

src/frames.cc

@@ -439,8 +439,8 @@ StackFrame::Type StackFrame::ComputeType(const StackFrameIteratorBase* iterator,
     if (!marker->IsSmi()) {
       if (maybe_function->IsSmi()) {
         return NONE;
-      } else if (FLAG_ignition && IsInterpreterFramePc(iterator->isolate(),
-                                                       *(state->pc_address))) {
+      } else if (IsInterpreterFramePc(iterator->isolate(),
+                                      *(state->pc_address))) {
         return INTERPRETED;
       } else {
         return JAVA_SCRIPT;

src/heap/mark-compact.cc

@@ -1636,7 +1636,7 @@ class MarkCompactCollector::EvacuateVisitorBase
       DCHECK_OBJECT_SIZE(size);
       DCHECK(IsAligned(size, kPointerSize));
       heap_->CopyBlock(dst_addr, src_addr, size);
-      if ((mode == kProfiled) && FLAG_ignition && dst->IsBytecodeArray()) {
+      if ((mode == kProfiled) && dst->IsBytecodeArray()) {
         PROFILE(heap_->isolate(),
                 CodeMoveEvent(AbstractCode::cast(src), dst_addr));
       }

src/ic/ic.cc

@@ -250,9 +250,8 @@ SharedFunctionInfo* IC::GetSharedFunctionInfo() const {
   // corresponding to the frame.
   StackFrameIterator it(isolate());
   while (it.frame()->fp() != this->fp()) it.Advance();
-  if (FLAG_ignition && it.frame()->type() == StackFrame::STUB) {
-    // Advance over bytecode handler frame.
-    // TODO(rmcilroy): Remove this once bytecode handlers don't need a frame.
+  if (it.frame()->type() == StackFrame::STUB) {
+    // We might need to advance over bytecode handler frame for Ignition.
     it.Advance();
   }
   JavaScriptFrame* frame = JavaScriptFrame::cast(it.frame());

src/isolate.cc

@@ -2559,9 +2559,7 @@ bool Isolate::Init(Deserializer* des) {
     }
     load_stub_cache_->Initialize();
     store_stub_cache_->Initialize();
-    if (FLAG_ignition || serializer_enabled()) {
-      interpreter_->Initialize();
-    }
+    interpreter_->Initialize();
 
     heap_.NotifyDeserializationComplete();
   }

src/log.cc

@@ -1484,8 +1484,6 @@ void Logger::LogCodeObjects() {
 }
 
 void Logger::LogBytecodeHandlers() {
-  if (!FLAG_ignition) return;
-
   const interpreter::OperandScale kOperandScales[] = {
 #define VALUE(Name, _) interpreter::OperandScale::k##Name,
       OPERAND_SCALE_LIST(VALUE)

test/cctest/test-log-stack-tracer.cc

@@ -81,9 +81,8 @@ static void construct_call(const v8::FunctionCallbackInfo<v8::Value>& args) {
   frame_iterator.Advance();
   CHECK(frame_iterator.frame()->is_construct());
   frame_iterator.Advance();
-  if (i::FLAG_ignition) {
+  if (frame_iterator.frame()->type() == i::StackFrame::STUB) {
     // Skip over bytecode handler frame.
-    CHECK(frame_iterator.frame()->type() == i::StackFrame::STUB);
     frame_iterator.Advance();
   }
   i::StackFrame* calling_frame = frame_iterator.frame();