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 asinhl = __asinhl
  
  #include "libm.h"
  
  static const long double
          ln2     = 6.931471805599453094172321214581765680755e-0001L,
--- 25,35 ----
  /*
   * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
! #pragma weak __asinhl = asinhl
  
  #include "libm.h"
  
  static const long double
          ln2     = 6.931471805599453094172321214581765680755e-0001L,