Changeset 20625a5 in rtems for c/src/lib

bsps/i386: use Pentimum instructions for pc586 and pc686 builds.

When GCC option -march is not specifies i386-rtems toolchain
defaults to i386 architecture instruction set. It does not
provide atomic instructions which results in really inefficient
atomic_fetch_or even on UP build.

SMP build is broken with i386 set because libatomic and GCC
generate infinite loop for atomic_fetch_add_4 used
in rtems_interrupt_lock_acquire

atomic_fetch_add_4:

push %ebp
mov %esp,%ebp
movl $0x5,0x10(%ebp)
pop %ebp
jmp atomic_fetch_add_4