[workaround] libpthread/nptl/sysdeps/unix/sysv/linux: .S-files build problems

[Douglas Mencken]

Build error:
make[2]: *** No rule to make target
`libpthread/nptl/sysdeps/unix/sysv/linux/powerpc/clone.c', needed by
`libc/libc.oS'.  Stop.
make[1]: *** [../lib/libc.so.0] Error 2

Looks like .S-suffixes are bad for them. So I just renamed them to
.c-files (at first, one-by-one to discover them all) to get uclibc to
be built.
Workaround:

cd "${uclibc_srcdir}"/libpthread/nptl/sysdeps/unix/sysv/linux/powerpc/
[ -f clone.c ] || mv clone.S clone.c
[ -f vfork.c ] || mv vfork.S vfork.c

cd "${uclibc_srcdir}"/libpthread/nptl/sysdeps/unix/sysv/linux/
[ -f open.c ] || mv open.S open.c
[ -f close.c ] || mv close.S close.c
[ -f read.c ] || mv read.S read.c
[ -f write.c ] || mv write.S write.c
[ -f waitpid.c ] || mv waitpid.S waitpid.c