backport: re PR target/91275 (__builtin_crypto_vpmsumd gives different results -O...

backport: re PR target/91275 (__builtin_crypto_vpmsumd gives different results -O[123] vs -O0)

[gcc]

2019-10-07  Bill Schmidt  <wschmidt@linux.ibm.com>

	Backport from mainline
	2019-10-01  Bill Schmidt  <wschmidt@linux.ibm.com>

	PR target/91275
	* config/rs6000/rs6000.c (rtx_is_swappable_p): Don't swap
	vpmsumd.

[gcc/testsuite]

2019-10-07  Bill Schmidt  <wschmidt@linux.ibm.com>

	Backport from mainline
	2019-10-01  Bill Schmidt  <wschmdit@linux.ibm.com>

	PR target/91275
	* gcc.target/powerpc/pr91275.c: New.

From-SVN: r276678