[Bug target/93177] PPC: Missing many useful platform intrinsics

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93177

--- Comment #19 from Iain Sandoe <iains at gcc dot gnu.org> ---
Created attachment 53779
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53779&action=edit
introduce ppc_intrinsics.h for powerpc*-darwin.

This takes the header from the GCC-4.x apple debt branch (as present in SVN:
r113478) and 
 - updates the license.
 - installs for powerpc*-darwin

It needs the test cases forward porting too.
However, it would be good to know if this solves the problems folks have
encountered here (if other ports want to try it, why only need to amend their
entry in gcc/config.gcc)