[Interpreter] Ensure ToBoolean bytecodes are correctly emitted at the start of basic blocks

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/compiler.h"
 #include "src/interpreter/control-flow-builders.h"
 #include "src/objects.h"
 #include "src/parser.h"
@@ skipping 356 matching lines @@
 
   // Visit declarations within the function scope.
   VisitDeclarations(scope()->declarations());
 
   // Visit statements in the function body.
   VisitStatements(info()->literal()->body());
 }
 
 
 void BytecodeGenerator::VisitBlock(Block* stmt) {
-  builder()->EnterBlock();
   if (stmt->scope() == NULL) {
     // Visit statements in the same scope, no declarations.
     VisitStatements(stmt->statements());
   } else {
     // Visit declarations and statements in a block scope.
     if (stmt->scope()->NeedsContext()) {
       VisitNewLocalBlockContext(stmt->scope());
       ContextScope scope(this, stmt->scope());
       VisitDeclarations(stmt->scope()->declarations());
       VisitStatements(stmt->statements());
     } else {
       VisitDeclarations(stmt->scope()->declarations());
       VisitStatements(stmt->statements());
     }
   }
-  builder()->LeaveBlock();
 }
 
 
 void BytecodeGenerator::VisitVariableDeclaration(VariableDeclaration* decl) {
   Variable* variable = decl->proxy()->var();
   VariableMode mode = decl->mode();
   // Const and let variables are initialized with the hole so that we can
   // check that they are only assigned once.
   bool hole_init = mode == CONST || mode == CONST_LEGACY || mode == LET;
   switch (variable->location()) {
@@ skipping 371 matching lines @@
   if (stmt->subject()->IsNullLiteral() ||
       stmt->subject()->IsUndefinedLiteral(isolate())) {
     // ForIn generates lots of code, skip if it wouldn't produce any effects.
     return;
   }
 
   LoopBuilder loop_builder(builder());
   ControlScopeForIteration control_scope(this, stmt, &loop_builder);
 
   // Prepare the state for executing ForIn.
-  builder()->EnterBlock();
   VisitForAccumulatorValue(stmt->subject());
   loop_builder.BreakIfUndefined();
   loop_builder.BreakIfNull();
 
   Register receiver = execution_result()->NewRegister();
   builder()->CastAccumulatorToJSObject();
   builder()->StoreAccumulatorInRegister(receiver);
   builder()->CallRuntime(Runtime::kGetPropertyNamesFast, receiver, 1);
   builder()->ForInPrepare(receiver);
   loop_builder.BreakIfUndefined();
@@ skipping 25 matching lines @@
   // even an empty body will have this assignment.
   Visit(stmt->body());
 
   // Increment the index and start loop again.
   builder()
       ->Bind(&continue_label)
       .LoadAccumulatorWithRegister(index)
       .CountOperation(Token::Value::ADD, language_mode_strength())
       .Jump(&condition_label);
 
-  // End of loop
-  builder()->Bind(&break_label).LeaveBlock();
+  // End of the loop.
+  builder()->Bind(&break_label);
 
   loop_builder.SetBreakTarget(break_label);
   loop_builder.SetContinueTarget(continue_label);
 }
 
 
 void BytecodeGenerator::VisitForOfStatement(ForOfStatement* stmt) {
   UNIMPLEMENTED();
 }
 
@@ skipping 1320 matching lines @@
 }
 
 
 int BytecodeGenerator::feedback_index(FeedbackVectorSlot slot) const {
   return info()->feedback_vector()->GetIndex(slot);
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8