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

vm/os.h

 // Copyright (c) 2011, 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.
 
 #ifndef VM_OS_H_
 #define VM_OS_H_
 
 #include "vm/globals.h"
 
 // Forward declarations.
@@ skipping 39 matching lines @@
 
   // Returns the stack size limit.
   static uword GetStackSizeLimit();
 
   // Returns number of available processor cores.
   static int NumberOfAvailableProcessors();
 
   // Sleep the currently executing thread for millis ms.
   static void Sleep(int64_t millis);
 
-  // Debug break.
-  static void DebugBreak();
-
   // Print formatted output to stdout/stderr for debugging.
   static void Print(const char* format, ...);
   static void PrintErr(const char* format, ...);
   static void VFPrint(FILE* stream, const char* format, va_list args);
   // Print formatted output info a buffer.
   // Does not write more than size characters (including the trailing '\0').
   // Returns the number of characters (excluding the trailing '\0') that would
   // been written if the buffer had been big enough.
   // If the return value is greater or equal than the given size then the output
   // has been truncated.
@@ skipping 14 matching lines @@
   static void Shutdown();
 
   static void Abort();
 
   static void Exit(int code);
 };
 
 }  // namespace dart
 
 #endif  // VM_OS_H_