Skip ms_abi attribute tests on x32

	* gcc.target/i386/pr57003.c: Skip on x32.
	* gcc.target/i386/pr59927.c: Likewise.
	* gcc.target/i386/pr60516.c: Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_9-branch@219091 138bc75d-0d04-0410-961f-82ee72b054a4