* sysdeps/hppa/bits/setjmp.h: Add _BITS_SETJMP_H preprocessor
protection and allow pthread.h to include bits/setjmp.h as well as
setjmp.h.
* sysdeps/m68k/bits/setjmp.h: Likewise.
* sysdeps/s390/bits/setjmp.h: Make sure only setjmp.h or pthread.h
are allow to include bits/setjmp.h.
* sysdeps/mips/bits/setjmp.h (_JMPBUF_UNWINDS): Cast rhs to match lhs
cast of address.
* sysdeps/sh/bits/setjmp.h: Likewise.