Miscellaneous sys/ucontext.h namespace fixes (bug 21457)

[Zack Weinberg]

On 06/19/2017 06:26 PM, Joseph Myers wrote:
> This patch fixes various miscellaneous namespace issues in
> sys/ucontext.h headers.
...
> 	[BZ #21457]
> 	* sysdeps/unix/sysv/linux/m68k/sys/ucontext.h (fpregset_t): Remove
> 	struct tag.
> 	* sysdeps/unix/sysv/linux/mips/sys/ucontext.h (fpregset_t):
> 	Likewise.
> 	* sysdeps/unix/sysv/linux/nios2/sys/ucontext.h (mcontext_t):
> 	Likewise.

These are OK.


> 	* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h (pt_regs):
> 	Declare struct type with __ctx.
> 	[__WORDSIZE != 32] (mcontext_t): Use __ctx with pt_regs struct
> 	tag.
> 	(ucontext_t) [__WORDSIZE == 32]: Use __ctx with pt_regs struct tag
> 	and regs field name.

This is also OK, although I am starting to wonder whether __ctx or
something like it should be in sys/cdefs.h.

> 	* sysdeps/unix/sysv/linux/sparc/
The SPARC changes are complicated enough that I think they need to be
reviewed by an architecture maintainer.

zw