[binutils-gdb] Implement the "get_siginfo_type" gdbarch method for FreeBSD architectures.

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 762c974a09746bda8a5d64ed3ee887adeae742b9 ***

Author: John Baldwin <jhb@FreeBSD.org>
Branch: master
Commit: 762c974a09746bda8a5d64ed3ee887adeae742b9

Implement the "get_siginfo_type" gdbarch method for FreeBSD architectures.

As with Linux architectures, cache the created type in the gdbarch when it
is first created.  Currently FreeBSD uses an identical siginfo type on
all architectures, so there is no support for architecture-specific fields.

gdb/ChangeLog:

	* fbsd-tdep.c (fbsd_gdbarch_data_handle, struct fbsd_gdbarch_data)
	(init_fbsd_gdbarch_data, get_fbsd_gdbarch_data)
	(fbsd_get_siginfo_type): New.
	(fbsd_init_abi): Install gdbarch "get_siginfo_type" method.
	(_initialize_fbsd_tdep): New.