rs6000: MMA type causes an ICE in ranger pass due to incompatible types

rs6000: MMA type causes an ICE in ranger pass due to incompatible types

PR97360 shows a problem in how we create our PXI and POI modes that cause
an ICE in the ranger pass.  The problem seems to be that the extra call
to build_distinct_type_copy() also creates new TYPE_{MIN,MAX}_VALUEs that
are not compatible/the same as the base type itself.  The simple "fix" is
to actually remove the unneeded build_distinct_type_copy(), since according
to richi, the types returned from make_unsigned_type() are already distinct.

gcc/

2020-10-21  Richard Biener  <rguenther@suse.de>

	PR target/97360
	* config/rs6000/rs6000-call.c (rs6000_init_builtins): Remove call to
	build_distinct_type_copy().

gcc/testsuite/

2020-10-21  Martin Liska  <mliska@suse.cz>

	PR target/97360
	* gcc.target/powerpc/pr97360.c: New test.

Co-authored-by: Andrew MacLeod <amacleod@redhat.com>
Co-authored-by: Martin Liska <mliska@suse.cz>