5261 libm should stop using synonyms.h

*** 25,41 ****
  /*
   * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
! #pragma weak fegetround = __fegetround
! #pragma weak fesetround = __fesetround
  
  #pragma weak fegetround96 = __fegetround
- #pragma weak fesetround96 = __fesetround96
  
- #include "fenv_synonyms.h"
  #include <fenv.h>
  #include <ucontext.h>
  #include <thread.h>
  #include "fex_handler.h"
  #include "fenv_inlines.h"
--- 25,39 ----
  /*
   * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
! #pragma weak __fegetround = fegetround
! #pragma weak __fesetround = fesetround
  
  #pragma weak fegetround96 = __fegetround
  
  #include <fenv.h>
  #include <ucontext.h>
  #include <thread.h>
  #include "fex_handler.h"
  #include "fenv_inlines.h"