Add support for enabling DCHECKs in release mode

src/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/v8.h"
 
 #include "src/ast.h"
 #include "src/ast-numbering.h"
 #include "src/code-factory.h"
 #include "src/codegen.h"
@@ skipping 1741 matching lines @@
   Isolate* isolate = code->GetIsolate();
   Address pc = code->instruction_start() + pc_offset;
 
   if (OSR_AFTER_STACK_CHECK == GetBackEdgeState(isolate, *code, pc)) {
     Code* patch = isolate->builtins()->builtin(Builtins::kOnStackReplacement);
     PatchAt(*code, pc, ON_STACK_REPLACEMENT, patch);
   }
 }
 
 
-#ifdef DEBUG
+#if DCHECK_IS_ON
 bool BackEdgeTable::Verify(Isolate* isolate, Code* unoptimized) {
   DisallowHeapAllocation no_gc;
   int loop_nesting_level = unoptimized->allow_osr_at_loop_nesting_level();
   BackEdgeTable back_edges(unoptimized, &no_gc);
   for (uint32_t i = 0; i < back_edges.length(); i++) {
     uint32_t loop_depth = back_edges.loop_depth(i);
     CHECK_LE(static_cast<int>(loop_depth), Code::kMaxLoopNestingMarker);
     // Assert that all back edges for shallower loops (and only those)
     // have already been patched.
     CHECK_EQ((static_cast<int>(loop_depth) <= loop_nesting_level),
              GetBackEdgeState(isolate,
                               unoptimized,
                               back_edges.pc(i)) != INTERRUPT);
   }
   return true;
 }
-#endif  // DEBUG
+#endif  // DCHECK_IS_ON
 
 
 FullCodeGenerator::EnterBlockScopeIfNeeded::EnterBlockScopeIfNeeded(
     FullCodeGenerator* codegen, Scope* scope, BailoutId entry_id,
     BailoutId declarations_id, BailoutId exit_id)
     : codegen_(codegen), scope_(scope), exit_id_(exit_id) {
   saved_scope_ = codegen_->scope();
 
   if (scope == NULL) {
     codegen_->PrepareForBailoutForId(entry_id, NO_REGISTERS);
@@ skipping 29 matching lines @@
   }
   codegen_->PrepareForBailoutForId(exit_id_, NO_REGISTERS);
   codegen_->scope_ = saved_scope_;
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal