ELF/BFD,GDB: Handle both variants of the 32-bit Linux core PRPSINFO note

ELF/BFD,GDB: Handle both variants of the 32-bit Linux core PRPSINFO note

Fix commit 70a38d42c5b3 ("New entry points for writing Linux NT_PRPSINFO
notes."), <https://sourceware.org/ml/binutils/2013-02/msg00023.html>,
and commit b3ac9c77560a ("Put more info in NT_PRPSINFO Linux notes"),
<https://sourceware.org/ml/binutils/2013-02/msg00024.html>, and handle
both variants of the 32-bit Linux core PRPSINFO note across all targets.

The 32-bit Linux core PRPSINFO note matches the 32-bit kernel structure,
defined as follows:

(gdb) ptype struct elf_prpsinfo
type = struct elf_prpsinfo {
    char pr_state;
    char pr_sname;
    char pr_zomb;
    char pr_nice;
    unsigned long pr_flag;
    __kernel_uid_t pr_uid;
    __kernel_gid_t pr_gid;
    pid_t pr_pid;
    pid_t pr_ppid;
    pid_t pr_pgrp;
    pid_t pr_sid;
    char pr_fname[16];
    char pr_psargs[80];
}
(gdb)

where the individual data types of most members are the same across all
32-bit Linux ports, with the exception of `__kernel_uid_t' and
`__kernel_gid_t'.  These are defined in <asm-generic/posix_types.h> as
32-bit `unsigned int' by default, however overridden as 16-bit `unsigned
short' in port-specific <asm/posix_types.h> for a few targets, mostly
earlier ports of Linux, specifically: ARM, CRIS, FR-V, M32R, m68k,
MN10300/AM33, s390, SuperH, SPARC and i386.

The default is the same as the PowerPC variant already handled, as from
the commits referred.  Make the special PowerPC case generic then,
removing the GDB part, and provide a backend flag to switch between the
two cases possible, with the 32-bit one being the default and the 16-bit
one explicitly selected.  Set the flag in the target backends affected.

	bfd/
	* elf-bfd.h (elf_backend_data): Add `linux_prpsinfo32_ugid16'
	member.
	(elfcore_write_ppc_linux_prpsinfo32): Remove prototype.
	* elf32-ppc.c (elfcore_write_ppc_linux_prpsinfo32): Remove.
	(elf_external_ppc_linux_prpsinfo32)
	(swap_ppc_linux_prpsinfo32_out): Move to...
	* elf-linux-core.h (elf_external_linux_prpsinfo32_ugid32)
	(swap_linux_prpsinfo32_ugid32_out): ... these.
	(elf_external_linux_prpsinfo32): Rename to...
	(elf_external_linux_prpsinfo32_ugid16): ... this.
	(swap_linux_prpsinfo32_out): Rename to...
	(swap_linux_prpsinfo32_ugid16_out): ... this.
	* elfxx-target.h [!elf_backend_linux_prpsinfo32_ugid16]
	(elf_backend_linux_prpsinfo32_ugid16): Define.
	(elfNN_bed): Initialize `linux_prpsinfo32_ugid16' member.
	* elf.c (elfcore_write_linux_prpsinfo32): Handle both variants
	of the 32-bit Linux core PRPSINFO note.
	* elf32-am33lin.c (elf_backend_linux_prpsinfo32_ugid16): Define.
	* elf32-arm.c (elf_backend_linux_prpsinfo32_ugid16): Define.
	* elf32-cris.c (elf_backend_linux_prpsinfo32_ugid16): Define.
	* elf32-frv.c (elf_backend_linux_prpsinfo32_ugid16): Define.
	* elf32-i386.c (elf_backend_linux_prpsinfo32_ugid16): Define.
	* elf32-m32r.c (elf_backend_linux_prpsinfo32_ugid16): Define.
	* elf32-m68k.c (elf_backend_linux_prpsinfo32_ugid16): Define.
	* elf32-s390.c (elf_backend_linux_prpsinfo32_ugid16): Define.
	* elf32-sh.c (elf_backend_linux_prpsinfo32_ugid16): Define.
	* elf32-sparc.c (elf_backend_linux_prpsinfo32_ugid16): Define.

	gdb/
	* ppc-linux-tdep.c (ppc_linux_init_abi): Remove call to
	`set_gdbarch_elfcore_write_linux_prpsinfo'.