5261 libm should stop using synonyms.h

*** 24,34 ****
  /*
   * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
! #pragma weak acoshf = __acoshf
  
  #include "libm.h"
  
  static const float zero = 0.0f;
  
--- 24,34 ----
  /*
   * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
! #pragma weak __acoshf = acoshf
  
  #include "libm.h"
  
  static const float zero = 0.0f;