Remove features/i386/amd64-*linux.c and features/i386/x32-*linux.c

gdb:

2017-09-05  Yao Qi  <yao.qi@linaro.org>

	* features/Makefile (XMLTOC): Remove i386/amd64XXX-linux.xml.
	* features/i386/amd64-avx-avx512-linux.c: Removed.
	* features/i386/amd64-avx-linux.c: Removed.
	* features/i386/amd64-avx-mpx-avx512-pku-linux.c: Removed.
	* features/i386/amd64-avx-mpx-linux.c: Removed.
	* features/i386/amd64-linux.c: Removed.
	* features/i386/amd64-mpx-linux.c: Removed.
	* features/i386/x32-avx-avx512-linux.c: Removed.
	* features/i386/x32-avx-linux.c: Removed.
	* features/i386/x32-linux.c: Removed.