10495 libc should know how many FPU exceptions there are

*** 60,71 ****
  #if defined(__STDC__) && !defined(_FILEDEFED)
  #define _FILEDEFED
  typedef __FILE FILE;
  #endif
  
- #define N_IEEE_EXCEPTION 5      /* Number of floating-point exceptions. */
- 
  typedef int sigfpe_code_type;   /* Type of SIGFPE code. */
  
  typedef void (*sigfpe_handler_type)();  /* Pointer to exception handler */
  
  #define SIGFPE_DEFAULT (void (*)())0    /* default exception handling */
--- 60,69 ----