Change rtems_panic() implementation and document this function

[Sebastian Huber]

The current rtems_panic() implementation is quite heavy weight. It depends on _exit() which calls the global destructors. It uses fprintf(stderr, ...) for output which depends on an initialized console device and the complex fprintf().

Introduce a new fatal source RTEMS_FATAL_SOURCE_PANIC for rtems_panic() and output via printk().

Document this function in Fatal Manager chapter.

Replace all BSP_panic() with rtems_panic().

[Sebastian Huber <sebastian.huber@…>]

In 15e19273/rtems:

sapi: New implementation of rtems_panic()

The previous rtems_panic() implementation was quite heavy weight. It
depended on _exit() which calls the global destructors. It used
fprintf(stderr, ...) for output which depends on an initialized console
device and the complex fprintf().

Introduce a new fatal source RTEMS_FATAL_SOURCE_PANIC for rtems_panic()
and output via vprintk().

Update #3244.

[Sebastian Huber <sebastian.huber@…>]

In 97c51c8/rtems-docs:

c-user: Document rtems_panic()

Close #3244.

[Sebastian Huber <sebastian.huber@…>]

In c934365f/rtems:

Update rtems_fatal_source_text()

Add RTEMS_FATAL_SOURCE_PANIC to rtems_fatal_source_text().

Update #3244.