[interpreter] Reachability is implied by live environment.

src/compiler/bytecode-graph-builder.cc

 // Copyright 2015 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.
 
 #include "src/compiler/bytecode-graph-builder.h"
 
 #include "src/compiler/bytecode-branch-analysis.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/operator-properties.h"
 #include "src/interpreter/bytecodes.h"
@@ skipping 597 matching lines @@
 
 
 void BytecodeGraphBuilder::VisitBytecodes() {
   BytecodeBranchAnalysis analysis(bytecode_array(), local_zone());
   analysis.Analyze();
   set_branch_analysis(&analysis);
   interpreter::BytecodeArrayIterator iterator(bytecode_array());
   set_bytecode_iterator(&iterator);
   while (!iterator.done()) {
     int current_offset = iterator.current_offset();
-    if (analysis.is_reachable(current_offset)) {
-      EnterAndExitExceptionHandlers(current_offset);
-      SwitchToMergeEnvironment(current_offset);
+    EnterAndExitExceptionHandlers(current_offset);
+    SwitchToMergeEnvironment(current_offset);
+    if (environment() != nullptr) {
       BuildLoopHeaderEnvironment(current_offset);
 
       switch (iterator.current_bytecode()) {
 #define BYTECODE_CASE(name, ...)       \
   case interpreter::Bytecode::k##name: \
     Visit##name();                     \
     break;
         BYTECODE_LIST(BYTECODE_CASE)
 #undef BYTECODE_CODE
       }
@@ skipping 1231 matching lines @@
 
 void BytecodeGraphBuilder::UpdateControlDependencyToLeaveFunction(Node* exit) {
   if (environment()->IsMarkedAsUnreachable()) return;
   environment()->MarkAsUnreachable();
   exit_controls_.push_back(exit);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8