[debugger] fix step-next for tail calls.

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/scopeinfo.h"
@@ skipping 653 matching lines @@
 
 
 void FullCodeGenerator::SetExpressionAsStatementPosition(Expression* expr) {
   if (expr->position() == RelocInfo::kNoPosition) return;
   bool recorded = RecordStatementPosition(masm_, expr->position());
   if (recorded && info_->is_debug()) {
     DebugCodegen::GenerateSlot(masm_, RelocInfo::DEBUG_BREAK_SLOT_AT_POSITION);
   }
 }
 
-
-void FullCodeGenerator::SetCallPosition(Expression* expr) {
+void FullCodeGenerator::SetCallPosition(Expression* expr,
+                                        TailCallMode tail_call_mode) {
   if (expr->position() == RelocInfo::kNoPosition) return;
   RecordPosition(masm_, expr->position());
   if (info_->is_debug()) {
+    RelocInfo::Mode mode = (tail_call_mode == TailCallMode::kAllow)
+                               ? RelocInfo::DEBUG_BREAK_SLOT_AT_TAIL_CALL
+                               : RelocInfo::DEBUG_BREAK_SLOT_AT_CALL;
     // Always emit a debug break slot before a call.
-    DebugCodegen::GenerateSlot(masm_, RelocInfo::DEBUG_BREAK_SLOT_AT_CALL);
+    DebugCodegen::GenerateSlot(masm_, mode);
   }
 }
 
 
 void FullCodeGenerator::VisitSuperPropertyReference(
     SuperPropertyReference* super) {
   __ CallRuntime(Runtime::kThrowUnsupportedSuperError);
 }
 
 
@@ skipping 1264 matching lines @@
   return var->mode() == CONST_LEGACY || var->scope()->is_nonlinear() ||
          var->initializer_position() >= proxy->position();
 }
 
 
 #undef __
 
 
 }  // namespace internal
 }  // namespace v8