Use general instruction/stack pointer convenience method instead of manually

src/google_breakpad/processor/dump_context.h

 // Copyright (c) 2014 Google Inc.
 // 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
@@ skipping 49 matching lines @@
   const MDRawContextMIPS*  GetContextMIPS() const;
   const MDRawContextPPC*   GetContextPPC() const;
   const MDRawContextPPC64* GetContextPPC64() const;
   const MDRawContextSPARC* GetContextSPARC() const;
   const MDRawContextX86*   GetContextX86() const;
 
   // A convenience method to get the instruction pointer out of the
   // MDRawContext, since it varies per-CPU architecture.
   bool GetInstructionPointer(uint64_t* ip) const;
 
+  // Similar to the GetInstructionPointer method, this method gets the stack
+  // pointer for all CPU architectures.
+  bool GetStackPointer(uint64_t* sp) const;
+
   // Print a human-readable representation of the object to stdout.
   void Print();
 
  protected:
   DumpContext();
 
   // Sets row CPU-specific context data for the names CPU type.
   void SetContextFlags(uint32_t context_flags);
   void SetContextX86(MDRawContextX86* x86);
   void SetContextPPC(MDRawContextPPC* ppc);
@@ skipping 23 matching lines @@
     MDRawContextMIPS*  ctx_mips;
   } context_;
 
   // Store this separately because of the weirdo AMD64 context
   uint32_t context_flags_;
 };
 
 }  // namespace google_breakpad
 
 #endif  // GOOGLE_BREAKPAD_PROCESSOR_DUMP_CONTEXT_H__