Revert of [debugger] remove debugger statement support from FCG/CS.

src/full-codegen/full-codegen.cc

 // Copyright 2012 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/full-codegen/full-codegen.h"
 
 #include "src/ast/ast-numbering.h"
 #include "src/ast/ast.h"
 #include "src/ast/prettyprinter.h"
 #include "src/ast/scopes.h"
@@ skipping 1210 matching lines @@
 }
 
 
 void FullCodeGenerator::VisitTryFinallyStatement(TryFinallyStatement* stmt) {
   // Exception handling is not supported.
   UNREACHABLE();
 }
 
 
 void FullCodeGenerator::VisitDebuggerStatement(DebuggerStatement* stmt) {
-  // Debugger statement is not supported.
-  UNREACHABLE();
+  Comment cmnt(masm_, "[ DebuggerStatement");
+  SetStatementPosition(stmt);
+
+  __ DebugBreak();
+  __ MaybeDropFrames();
+
+  PrepareForBailoutForId(stmt->DebugBreakId(), BailoutState::NO_REGISTERS);
 }
 
 
 void FullCodeGenerator::VisitCaseClause(CaseClause* clause) {
   UNREACHABLE();
 }
 
 
 void FullCodeGenerator::VisitConditional(Conditional* expr) {
   Comment cmnt(masm_, "[ Conditional");
@@ skipping 355 matching lines @@
   return info_->has_simple_parameters();
 }
 
 FunctionLiteral* FullCodeGenerator::literal() const { return info_->literal(); }
 
 #undef __
 
 
 }  // namespace internal
 }  // namespace v8