Stop a resource leak

Stops a resource leak in the event that the system cannot malloc
Initialize the string before replacing characters
bsp/xilinx-zynq: Add cache support
libblock: Avoid uninitialized variable
score: PR2140: _Thread_queue_Extract()

Return if the executing context performed the extract operation since
interrupts may interfere.
score: PR2140: Fix _Thread_queue_Process_timeout()

The _Thread_queue_Process_timeout() operation had several race
conditions in the event of nested interrupts.  Protect the critical
sections via disabled interrupts.
score: Delete unused function parameter
bsps: Add and use CLOCK_DRIVER_ISRS_PER_TICK_VALUE

pc386 set CLOCK_DRIVER_ISRS_PER_TICK to a
string rather than a numeric value. Add
CLOCK_DRIVER_ISRS_PER_TICK_VALUE and
other clean up on the clock driver.
RFS: Use unprotected chain operations

This area is protected by the RFS file system instance lock.
libblock: Use unprotected chain extract

This area is protected by the media mutex.
bsps: Fix header includes
score: Add and use CHAIN_INITIALIZER_ONE_NODE().

Add and use CHAIN_NODE_INITIALIZER_ONE_NODE_CHAIN(),
RTEMS_CHAIN_INITIALIZER_ONE_NODE() and
RTEMS_CHAIN_NODE_INITIALIZER_ONE_NODE_CHAIN().
posix: Protect access to _POSIX_signals_Vectors

Assume the sigaction() is called only from thread context.  Protect
against concurrent sigaction() invocations by different threads.
Filesystem: Use unprotected chain operations

This area is protected by the IO library mutex.
ringbuf: Add SMP support
rtems: Add SMP support for signals

Add and use _ASR_Get_posted_signals().  The post-switch handler is not
protected by disabled thread dispatching.  Use proper SMP lock for
signal management.
posix: _POSIX_signals_Clear_process_signals()

Do not disable interrupts since the caller did this already.
sptests/spnsext01: Add SMP support
sptests/spthreadq01: Add SMP support
score: Add SMP support to _Watchdog_Report_chain()