Control profiling/debugger support from build script

src/x64/cfg-x64.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 94 matching lines @@
   Comment cmnt(masm, "[ ExitNode");
   if (FLAG_trace) {
     __ push(rax);
     __ CallRuntime(Runtime::kTraceExit, 1);
   }
   __ RecordJSReturn();
   __ movq(rsp, rbp);
   __ pop(rbp);
   int count = CfgGlobals::current()->fun()->scope()->num_parameters();
   __ ret((count + 1) * kPointerSize);
+#ifdef ENABLE_DEBUGGER_SUPPORT
   // Add padding that will be overwritten by a debugger breakpoint.
   // "movq rsp, rbp; pop rbp" has length 4.  "ret k" has length 3.
   const int kPadding = Debug::kX64JSReturnSequenceLength - 4 - 3;
   for (int i = 0; i < kPadding; ++i) {
     __ int3();
   }
+#endif
 }
 
 
 void PropLoadInstr::Compile(MacroAssembler* masm) {
   // The key should not be on the stack---if it is a compiler-generated
   // temporary it is in the accumulator.
   ASSERT(!key()->is_on_stack());
 
   Comment cmnt(masm, "[ Load from Property");
   // If the key is known at compile-time we may be able to use a load IC.
@@ skipping 182 matching lines @@
       break;
     case NOT_ALLOCATED:
       UNREACHABLE();
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal