Fix issue 1968, replace usage of inline 'asm' constructs in 'stack alignment', 'jump to exception h…

vm/os_macos.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/os.h"
 
 #include <errno.h>
 #include <limits.h>
 #include <mach/mach.h>
 #include <mach/clock.h>
@@ skipping 86 matching lines @@
   return sysconf(_SC_NPROCESSORS_ONLN);
 }
 
 
 void OS::Sleep(int64_t millis) {
   // TODO(5411554):  For now just use usleep we may have to revisit this.
   usleep(millis * 1000);
 }
 
 
-void OS::DebugBreak() {
-#if defined(HOST_ARCH_X64) || defined(HOST_ARCH_IA32)
-  asm("int $3");
-#else
-#error Unsupported architecture.
-#endif
-}
-
-
 void OS::Print(const char* format, ...) {
   va_list args;
   va_start(args, format);
   VFPrint(stdout, format, args);
   va_end(args);
 }
 
 
 void OS::VFPrint(FILE* stream, const char* format, va_list args) {
   vfprintf(stream, format, args);
@@ skipping 40 matching lines @@
 void OS::Abort() {
   abort();
 }
 
 
 void OS::Exit(int code) {
   exit(code);
 }
 
 }  // namespace dart