libio: fmemopen rewrite to POSIX compliance

libio: fmemopen rewrite to POSIX compliance

This patch added a new fmemopen version, for glibc 2.22, that aims to be
POSIX complaint.  It fixes some long-stading glibc fmemopen issues, such
as:

* it changes the way fseek with SEEK_END works on fmemopen to seek
  relative to buffer size instead of first '\0'.  This is default mode and
  'b' opening mode does not change internal behavior (bz#6544).

* fix apending opening mode to use as start position either first null
  byte of len specified in function call (bz#13152 and #13151).

* remove binary option 'b' and internal different handling (bz#12836)

* fix seek/SEE_END with negative values (bz#14292).

A compatibility symbol is provided to with old behavior for older symbols
version (2.2.5).

	* include/stdio.h (fmemopen): Remove hidden prototype.
	(__fmemopen): Add new hidden prototype.
	* libio/Makefile: Add oldfmemopen object.
	* libio/Versions [GLIBC_2.22]: Add new fmemopen symbol.
	* libio/fmemopen.c (__fmemopen): Function rewrite to be POSIX
	compliance.
	* libio/oldfmemopen.c: New file: old fmemopen implementation for
	symbol compatibility.
	* stdio-common/Makefile [tests]: Add new tst-fmemopen3.
	* stdio-common/psiginfo.c [psiginfo]: Call __fmemopen instead of
	fmemopen.
	* stdio-common/tst-fmemopen3.c: New file: more fmemopen tests, focus
	on append and read mode.
	* sysdeps/unix/sysv/linux/aarch64/libc.abilist [GLIBC_2.22]: Add
	fmemopen.
	* sysdeps/unix/sysv/linux/alpha/libc.abilist [GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/arm/libc.abilist [GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/i386/libc.abilist [GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/ia64/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/sh/libc.abilist [GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/hppa/libc.abilist [GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/nios2/libc.abilist [GLIBC_2.22]: Likewise.