7159 libc-tests build failed on sparc

*** 73,85 ****
  
  static pthread_attr_t pgn_attr;
  static pthread_attr_t pgn_thr_attr;
  static pthread_barrier_t pgn_barrier;
  
- #ifdef  __sparc
- #define gregs   __gregs
- #endif
  
  /*
   * Verify that the stack pointer of a context is consistent with where the
   * attributes indicate.
   */
--- 73,82 ----
*** 98,110 ****
          sp = ctx.uc_mcontext.gregs[R_SP];
          VERIFY3U(sp, >, (uintptr_t)stk);
          VERIFY3U(sp, <, (uintptr_t)stk + stksz);
  }
  
- #ifdef  __sparc
- #undef  gregs
- #endif
  
  static void
  pgn_test_fini(void)
  {
          int ret;
--- 95,104 ----