PR target/71958: Error on -mx32 with -mabi=ms

PR target/71958: Error on -mx32 with -mabi=ms

gcc/ChangeLog:
2017-08-11  Daniel Santos  <daniel.santos@pobox.com>

	* config/i386/i386.c (ix86_option_override_internal): Error when
	-mx32 is combined with -mabi=ms.
	(ix86_function_type_abi): Limit errors for mixing -mx32 with
	attribute ms_abi.

gcc/testsuite/ChangeLog:
2017-08-11  Daniel Santos  <daniel.santos@pobox.com>

	* gcc.target/i386/pr71958.c: New test to verify error on -mx32
	and -mabi=ms
 	* gcc.target/i386/pr64409.c: Modify to only run on x32.
	* gcc.target/i386/pr46470.c: Modify to skip x32 target.
 	* gcc.target/i386/pr66275.c: Likewise.
 	* gcc.target/i386/pr68018.c: Likewise.

From-SVN: r251287