Add bound related fields to the siginfo structure

Add bound related fields to the siginfo structure

Both Linux and glibc have introduced bound related fields in the
segmentation fault fields of the siginfo_t type. Add the new fields
to our x86's siginfo_t type too.

Kernel patch:
http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?id=ee1b58d36aa1b5a79eaba11f5c3633c88231da83

Glibc patch:
http://repo.or.cz/w/glibc.git/commit/d4358b51c26a634eb885955aea06cad26af6f696

2016-02-02  Walfred Tedeschi  <walfred.tedeschi@intel.com>

gdb/ChangeLog:

	* linux-tdep.c (linux_get_siginfo_type): Add the _addr_bnd
	structure to the siginfo if extra_fields contains
	LINUX_SIGINFO_FIELD_ADDR_BND.