[binutils-gdb] [PowerPC] Disable regsets using zero sizes in gdbserver

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 7273b5fc4baef93f8caaed678476e8cb3625338d ***

Author: Pedro Franco de Carvalho <pedromfc@linux.vnet.ibm.com>
Branch: master
Commit: 7273b5fc4baef93f8caaed678476e8cb3625338d

[PowerPC] Disable regsets using zero sizes in gdbserver

Currently the linux-ppc-low.c fill/store functions for extended
regsets check whether they should execute by using the global hwcap
variable.

This patch explicitly sets the regset sizes to zero when needed to
disable them instead, so that the fill/store functions are not called
in the first place by regsets_fetch_inferior_registers in linux-low.c.

gdb/gdbserver/ChangeLog:
2018-05-22  Pedro Franco de Carvalho  <pedromfc@linux.vnet.ibm.com>

	* linux-ppc-low.c (ppc_fill_vsxregset): Remove ppc_hwcap check.
	(ppc_store_vsxregset): Likewise.
	(ppc_fill_vrregset): Likewise.
	(ppc_store_vrregset): Likewise.
	(ppc_fill_evrregset): Likewise.
	(ppc_store_evrregset): Likewise.
	(ppc_regsets): Set VSX/VR/EVR regset sizes to 0.
	(ppc_arch_setup): Iterate through ppc_regsets and set sizes when
	needed.