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 asinh = __asinh
  
  /* INDENT OFF */
  /*
   * asinh(x)
   * Method :
--- 25,35 ----
  /*
   * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
! #pragma weak __asinh = asinh
  
  /* INDENT OFF */
  /*
   * asinh(x)
   * Method :
*** 41,51 ****
   *               := sign(x)*log(2|x|+1/(|x|+sqrt(x*x+1))) if|x| > 2, else
   *               := sign(x)*log1p(|x|+x^2/(1+sqrt(1+x^2)))
   */
  /* INDENT ON */
  
- #include "libm_synonyms.h"      /* __asinh */
  #include "libm_macros.h"
  #include <math.h>
  
  static const double xxx[] = {
  /* one */       1.00000000000000000000e+00,     /* 3FF00000, 00000000 */
--- 41,50 ----