sparc: More reliable bad trap handling

Statically initialize the trap table in start.S to jump to _SPARC_Bad_trap()
for all unexpected traps.  This enables a proper RTEMS fatal error handling
right from the start.  Do not rely on the stack and register settings which
caused an unexpected trap.  Use the ISR stack of the processor to do the fatal
error handling.  Save the full context which caused the trap.  Fatal error
handler may use it for error logging.

Unify the _CPU_Exception_frame_print() implementations and move it to cpukit.

Update #4459.

bsps/sparc/leon2/start/bspstart.c

@@ -108,8 +108,6 @@ struct drvmgr_bus_res leon2_amba_res __attribute__((weak)) =
  */
 static void leon2_pre_driver_hook( void )
 {
-  bsp_spurious_initialize();
-
   /* Initialize shared interrupt handling, must be done after IRQ
    * controller has been found and initialized.
    */