debug/strace: pump version to 4.7 and 4.8

Pump version for strace to 4.7 and 4.8.
Add patch from strace mainline.


Work around conflict between <sys/ptrace.h> and <linux/ptrace.h>

Since glibc-2.18~39 <sys/ptrace.h> defines ptrace_peeksiginfo_args
which collides with <linux/ptrace.h>.

* configure.ac: Check for `struct ptrace_peeksiginfo_args' in
<sys/ptrace.h>.
* process.c: Work around potential conflict between <sys/ptrace.h>
and <linux/ptrace.h> by redefining ptrace_peeksiginfo_args.
* signal.c: Likewise.
* syscall.c: Likewise.
* util.c: Likewise.
http://sourceforge.net/p/strace/code/ci/0b4060f61f1bb101b5d8d084714b7d2feacdb199/

Signed-off-by: "Daniel Zimmermann" <netzimme@gmail.com>
Message-Id: <67b082cf1cdc8276eb4a.1385366288@haus-VirtualBox>
Patchwork-Id: 293842

# Options specific to crosstool-NG acting as a backend

config IS_A_BACKEND

    string

    option env="CT_IS_A_BACKEND"

config BACKEND

    bool

    default y if IS_A_BACKEND = "y" || IS_A_BACKEND = "Y"

config BACKEND_ARCH

    string

    option env="CT_BACKEND_ARCH"

config BACKEND_KERNEL

    string

    option env="CT_BACKEND_KERNEL"

config BACKEND_LIBC

    string

    option env="CT_BACKEND_LIBC"