5261 libm should stop using synonyms.h

*** 25,35 ****
  /*
   * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
! #pragma weak acosh = __acosh
  
  /* INDENT OFF */
  /*
   * acosh(x)
   * Method :
--- 25,35 ----
  /*
   * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
! #pragma weak __acosh = acosh
  
  /* INDENT OFF */
  /*
   * acosh(x)
   * Method :
*** 44,54 ****
   *      acosh(x) is NaN with signal if x < 1.
   *      acosh(NaN) is NaN without signal.
   */
  /* INDENT ON */
  
- #include "libm_synonyms.h"      /* __acosh, __log, __log1p */
  #include "libm_protos.h"        /* _SVID_libm_error */
  #include "libm_macros.h"
  #include <math.h>
  
  static const double
--- 44,53 ----