Changeset e8512eb in rtems for c/src/lib/libc/malloc.c

incorporate Tony's patches:

+ c/src/lib/libc/support/generic/malloc.c did not initialize the

sbrk amount

+ _Thread_Handler in c/src/exec/rtems/thread.c left a window

during the begin extension which could result in a context switch

fixed places which did not correctly distinguish between an
CPU_isr and a CPU_isr_entry.