5261 libm should stop using synonyms.h

*** 24,34 ****
  /*
   * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
! #pragma weak exp = __exp
  
  /*
   * exp(x)
   * Hybrid algorithm of Peter Tang's Table driven method (for large
   * arguments) and an accurate table (for small arguments).
--- 24,34 ----
  /*
   * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
! #pragma weak __exp = exp
  
  /*
   * exp(x)
   * Hybrid algorithm of Peter Tang's Table driven method (for large
   * arguments) and an accurate table (for small arguments).