[Bug target/81622] [7/8 Regression] ICE on invalid altivec code with ppc64{,le}

["wschmidt at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81622

--- Comment #7 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
This code was reviewed and approved by Richard back when it was first written.

It's been some time since this was written, so I don't recall the origin of the
array type, but it was definitely necessary.  There are probably some test
cases from the original patch submission that show this.  I would have to go
digging to find that.

As stated in the submission note, the real long-term fix for this is to have
these built-in functions handled during gimple built-in folding instead.  I
wasn't aware of that as a target-hook option at the time this code went in. 
Gimple built-in folding would be much simpler since the grotty work of parsing
and error handling is behind us.  This is on the list to be done, but hasn't
been completed yet.