[interpreter] Elide OSR polling from fake loops.

src/interpreter/bytecode-generator.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/interpreter/bytecode-generator.h"
 
 #include "src/ast/scopes.h"
 #include "src/code-stubs.h"
 #include "src/compiler.h"
 #include "src/interpreter/bytecode-flags.h"
@@ skipping 1034 matching lines @@
 void BytecodeGenerator::VisitIterationBody(IterationStatement* stmt,
                                            LoopBuilder* loop_builder) {
   ControlScopeForIteration execution_control(this, stmt, loop_builder);
   builder()->StackCheck(stmt->position());
   Visit(stmt->body());
   loop_builder->SetContinueTarget();
 }
 
 void BytecodeGenerator::VisitDoWhileStatement(DoWhileStatement* stmt) {
   LoopBuilder loop_builder(builder());
-  VisitIterationHeader(stmt, &loop_builder);
   if (stmt->cond()->ToBooleanIsFalse()) {
     VisitIterationBody(stmt, &loop_builder);
   } else if (stmt->cond()->ToBooleanIsTrue()) {
+    VisitIterationHeader(stmt, &loop_builder);
     VisitIterationBody(stmt, &loop_builder);
     loop_builder.JumpToHeader();
   } else {
+    VisitIterationHeader(stmt, &loop_builder);
     VisitIterationBody(stmt, &loop_builder);
     builder()->SetExpressionAsStatementPosition(stmt->cond());
     VisitForAccumulatorValue(stmt->cond());
     loop_builder.JumpToHeaderIfTrue();
   }
   loop_builder.EndLoop();
 }
 
 void BytecodeGenerator::VisitWhileStatement(WhileStatement* stmt) {
   if (stmt->cond()->ToBooleanIsFalse()) {
@@ skipping 2164 matching lines @@
   return execution_context()->scope()->language_mode();
 }
 
 int BytecodeGenerator::feedback_index(FeedbackVectorSlot slot) const {
   return TypeFeedbackVector::GetIndex(slot);
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8