This patch fixes test case failures on arm targets due to '-mstructure-size-boundary' being deprecated. The test cases were failing because a warning was being issued and due to the fact that the size of packed and unpacked structures is the same after deprecating '-mstructure-size-boundary'

Okay for trunk?

2017-08-04  Michael Collison  <michael.collison@arm.com>

	* testsuite/g++.dg/ext/packed8.C: Skip test for arm_eabi.
	* testsuite/g++.dg/init/array16.C: Skip test for arm_eabi.
	* testsuite/g++.dg/other/crash-4.C: Skip test for arm_eabi.
	* testsuite/gcc.dg/builtin-stringop-chk-1.c: Skip test for arm_eabi.