Use general instruction/stack pointer convenience method instead of manually

src/google_breakpad/common/minidump_cpu_sparc.h

 /* Copyright (c) 2006, 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 120 matching lines @@
   /* Floating-Point Registers State register (FPRS) for SPARC V9
    * TBR for for SPARC V7/V8
    */
   uint64_t     fprs;
 
   /* The next field is included with MD_CONTEXT_SPARC_FLOATING_POINT */
   MDFloatingSaveAreaSPARC float_save;
 
 } MDRawContextSPARC;  /* CONTEXT_SPARC */
 
+/* Indices into g_r for registers with a dedicated or conventional purpose. */
+enum MDSPARCRegisterNumbers {
+  MD_CONTEXT_SPARC_REG_SP = 14
+};
+
 /* For (MDRawContextSPARC).context_flags.  These values indicate the type of
  * context stored in the structure.  MD_CONTEXT_SPARC is Breakpad-defined.  Its
  * value was chosen to avoid likely conflicts with MD_CONTEXT_* for other
  * CPUs. */
 #define MD_CONTEXT_SPARC                 0x10000000
 #define MD_CONTEXT_SPARC_CONTROL         (MD_CONTEXT_SPARC | 0x00000001)
 #define MD_CONTEXT_SPARC_INTEGER         (MD_CONTEXT_SPARC | 0x00000002)
 #define MD_CONTEXT_SAPARC_FLOATING_POINT (MD_CONTEXT_SPARC | 0x00000004)
 #define MD_CONTEXT_SAPARC_EXTRA          (MD_CONTEXT_SPARC | 0x00000008)
 
 #define MD_CONTEXT_SPARC_FULL            (MD_CONTEXT_SPARC_CONTROL | \
                                           MD_CONTEXT_SPARC_INTEGER)
 
 #define MD_CONTEXT_SPARC_ALL             (MD_CONTEXT_SPARC_FULL | \
                                           MD_CONTEXT_SAPARC_FLOATING_POINT | \
                                           MD_CONTEXT_SAPARC_EXTRA)
 
 #endif /* GOOGLE_BREAKPAD_COMMON_MINIDUMP_CPU_SPARC_H__ */