Fix more namespace issues in sys/ucontext.h (bug 21457).

Continuing the fixes for namespace issues in sys/ucontext.h, this
patch moves various symbols into the implementation namespace in the
absence of __USE_MISC.  As with previous changes, it is nonexhaustive,
just covering more straightforward cases.

Structure fields are generally changed to have a prefix __ in the
absence of __USE_MISC, via a macro __ctx (used without a space before
the open parenthesis, since the result is a single identifier).
Various macros such as NGREG also have leading __ added.  No changes
are made to structure tags (and thus to C++ name mangling), except
that in the (unused) file sysdeps/i386/sys/ucontext.h, structures
defined inside other structures as the type for a field have their
tags removed in the non-__USE_MISC case (those structure tags would
not in any case have been visible in C++, because in C++ the scope of
such a tag is limited to the containing structure).  No changes are
made to the contents of bits/sigcontext.h, or to whether it is
included.  Because of remaining namespace issues, this patch does not
yet fix the bug or allow any XFAILs to be removed.

Tested for x86_64 and x86, and with build-many-glibcs.py.

	[BZ #21457]
	* sysdeps/arm/sys/ucontext.h (NGREG): Rename to __NGREG and define
	NGREG to __NGREG if [__USE_MISC].
	(gregset_t): Define using __NGREG.
	(__ctx): New macro.
	(mcontext_t): Use __ctx in defining fields.
	* sysdeps/i386/sys/ucontext.h (NGREG): Rename to __NGREG and
	define NGREG to __NGREG if [__USE_MISC].
	(gregset_t): Define using __NGREG.
	(__ctx): New macro.
	(__ctxt): Likewise.
	(fpregset_t): Use __ctx and __ctxt in defining fields.
	(mcontext_t): Likewise.
	* sysdeps/m68k/sys/ucontext.h (NGREG): Rename to __NGREG and
	define NGREG to __NGREG if [__USE_MISC].
	(gregset_t): Define using __NGREG.
	(__ctx): New macro.
	(mcontext_t): Use __ctx in defining fields.
	* sysdeps/mips/sys/ucontext.h (NGREG): Rename to __NGREG and
	define NGREG to __NGREG if [__USE_MISC].
	(gregset_t): Define using __NGREG.
	(__ctx): New macro.
	(fpregset_t): Use __ctx in defining fields.
	(mcontext_t): Likewise.
	* sysdeps/unix/sysv/linux/alpha/sys/ucontext.h (NGREG): Rename to
	__NGREG and define NGREG to __NGREG if [__USE_MISC].
	(gregset_t): Define using __NGREG.
	(NFPREG): Rename to __NFPREG and define NFPREG to __NFPREG if
	[__USE_MISC].
	(fpregset_t): Define using __NFPREG.
	* sysdeps/unix/sysv/linux/m68k/sys/ucontext.h (NGREG): Rename to
	__NGREG and define NGREG to __NGREG if [__USE_MISC].
	(gregset_t): Define using __NGREG.
	(__ctx): New macro.
	(fpregset_t): Use __ctx in defining fields.
	(mcontext_t): Likewise.
	* sysdeps/unix/sysv/linux/mips/sys/ucontext.h (NGREG): Rename to
	__NGREG and define NGREG to __NGREG if [__USE_MISC].
	(NFPREG): Rename to __NFPREG and define NFPREG to __NFPREG if
	[__USE_MISC].
	(gregset_t): Define using __NGREG.
	(__ctx): New macro.
	(fpregset_t): Use __ctx in defining fields.
	(mcontext_t): Likewise.
	* sysdeps/unix/sysv/linux/nios2/sys/ucontext.h (__ctx): New macro.
	(mcontext_t): Use __ctx in defining fields.
	* sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h (__ctx): New
	macro.
	[__WORDSIZE == 32] (NGREG): Rename to __NGREG and define NGREG to
	__NGREG if [__USE_MISC].
	[__WORDSIZE == 32] (gregset_t): Define using __NGREG.
	[__WORDSIZE == 32] (fpregset_t): Use __ctx in defining fields.
	(mcontext_t): Likewise.
	[__WORDSIZE != 32] (NGREG): Rename to __NGREG and define NGREG to
	__NGREG if [__USE_MISC].
	[__WORDSIZE != 32] (NFPREG): Rename to __NFPREG and define NFPREG
	to __NFPREG if [__USE_MISC].
	[__WORDSIZE != 32] (NVRREG): Rename to __NVRREG and define NVRREG
	to __NVRREG if [__USE_MISC].
	[__WORDSIZE != 32] (gregset_t): Define using __NGREG.
	[__WORDSIZE != 32] (fpregset_t): Define using __NFPREG.
	[__WORDSIZE != 32] (vscr_t): Use __ctx in defining fields.
	[__WORDSIZE != 32] (vrregset_t): Likewise.
	[__WORDSIZE != 32] (mcontext_t): Likewise.
	* sysdeps/unix/sysv/linux/s390/sys/ucontext.h (__ctx): New macro.
	(__psw_t): Use __ctx in defining fields.
	(NGREG): Rename to __NGREG and define NGREG to __NGREG if
	[__USE_MISC].
	(gregset_t): Define using __NGREG.
	(fpreg_t): Use __ctx in defining fields.
	(fpregset_t): Likewise.
	(mcontext_t): Likewise.
	* sysdeps/unix/sysv/linux/sh/sys/ucontext.h (NGREG): Rename to
	__NGREG and define NGREG to __NGREG if [__USE_MISC].
	(gregset_t): Define using __NGREG.
	(NFPREG): Rename to __NFPREG and define NFPREG to __NFPREG if
	[__USE_MISC].
	(fpregset_t): Define using __NFPREG.
	(__ctx): New macro.
	(mcontext_t): Use __ctx in defining fields.
	* sysdeps/unix/sysv/linux/x86/sys/ucontext.h (__ctx): New macro.
	[__x86_64__] (NGREG): Rename to __NGREG and define NGREG to
	__NGREG if [__USE_MISC].
	[__x86_64__] (gregset_t): Define using __NGREG.
	[__x86_64__] (struct _libc_fpxreg): Use __ctx in defining fields.
	[__x86_64__] (struct _libc_fpstate): Likewise.
	[__x86_64__] (mcontext_t): Likewise.
	[!__x86_64__] (NGREG): Rename to __NGREG and define NGREG to
	__NGREG if [__USE_MISC].
	[!__x86_64__] (gregset_t): Define using __NGREG.
	[!__x86_64__] (struct _libc_fpreg): Use __ctx in defining fields.
	[!__x86_64__] (struct _libc_fpstate): Likewise.
	[!__x86_64__] (mcontext_t): Likewise.

1 files changed, 31 insertions, 17 deletions

diff --git a/sysdeps/unix/sysv/linux/sh/sys/ucontext.h b/sysdeps/unix/sysv/linux/sh/sys/ucontext.h
index 7444298957..d44f95e0f9 100644
--- a/sysdeps/unix/sysv/linux/sh/sys/ucontext.h
+++ b/sysdeps/unix/sysv/linux/sh/sys/ucontext.h
@@ -30,10 +30,13 @@
 typedef int greg_t;
 
 /* Number of general registers.  */
-#define NGREG	16
+#define __NGREG	16
+#ifdef __USE_MISC
+# define NGREG	__NGREG
+#endif
 
 /* Container for all general registers.  */
-typedef greg_t gregset_t[NGREG];
+typedef greg_t gregset_t[__NGREG];
 
 #ifdef __USE_MISC
 /* Number of each register is the `gregset_t' array.  */
@@ -77,29 +80,40 @@ enum
 typedef int freg_t;
 
 /* Number of FPU registers.  */
-#define NFPREG	16
+#define __NFPREG	16
+#ifdef __USE_MISC
+# define NFPREG	__NFPREG
+#endif
 
 /* Structure to describe FPU registers.  */
-typedef freg_t fpregset_t[NFPREG];
+typedef freg_t fpregset_t[__NFPREG];
+
+#ifdef __USE_MISC
+# define __ctx(fld) fld
+#else
+# define __ctx(fld) __ ## fld
+#endif
 
 /* Context to describe whole processor state.  */
 typedef struct
   {
-    unsigned int oldmask;
-    gregset_t gregs;
-    unsigned int pc;
-    unsigned int pr;
-    unsigned int sr;
-    unsigned int gbr;
-    unsigned int mach;
-    unsigned int macl;
-    fpregset_t fpregs;
-    fpregset_t xfpregs;
-    unsigned int fpscr;
-    unsigned int fpul;
-    unsigned int ownedfp;
+    unsigned int __ctx(oldmask);
+    gregset_t __ctx(gregs);
+    unsigned int __ctx(pc);
+    unsigned int __ctx(pr);
+    unsigned int __ctx(sr);
+    unsigned int __ctx(gbr);
+    unsigned int __ctx(mach);
+    unsigned int __ctx(macl);
+    fpregset_t __ctx(fpregs);
+    fpregset_t __ctx(xfpregs);
+    unsigned int __ctx(fpscr);
+    unsigned int __ctx(fpul);
+    unsigned int __ctx(ownedfp);
   } mcontext_t;
 
+#undef __ctx
+
 /* Userlevel context.  */
 typedef struct ucontext
   {