Introduce intrinsic to expose debug state to generated code.

src/arm64/full-codegen-arm64.cc

 // Copyright 2013 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"
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 3720 matching lines @@
   __ B(&done);
 
   __ Bind(&bailout);
   // Returning undefined will force slower code to handle it.
   __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
   __ Bind(&done);
   context()->Plug(result);
 }
 
 
+void FullCodeGenerator::EmitDebugIsActive(CallRuntime* expr) {
+  ASSERT(expr->arguments()->length() == 0);
+  ExternalReference debug_is_active =
+      ExternalReference::debug_is_active_address(isolate());
+  __ Mov(x10, debug_is_active);
+  __ Ldrb(x0, MemOperand(x10));
+  __ SmiTag(x0);
+  context()->Plug(x0);
+}
+
+
 void FullCodeGenerator::VisitCallRuntime(CallRuntime* expr) {
   if (expr->function() != NULL &&
       expr->function()->intrinsic_type == Runtime::INLINE) {
     Comment cmnt(masm_, "[ InlineRuntimeCall");
     EmitInlineRuntimeCall(expr);
     return;
   }
 
   Comment cmnt(masm_, "[ CallRunTime");
   ZoneList<Expression*>* args = expr->arguments();
@@ skipping 1142 matching lines @@
   return previous_;
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64