PowerPC Altivec does not support add and subtract of 64-bit elements.
Prepare for that configuration by not assuming the operation is
universally supported.
Backports commit ce27c5d1a38e93da38653af71fb468c5eded4c7b from qemu
It's either "GNU *Library* General Public version 2" or "GNU Lesser
General Public version *2.1*", but there was no "version 2.0" of the
"Lesser" library. So assume that version 2.1 is meant here.
Backports commit fb0343d5b4dd4b9b9e96e563d913a3e0c709fe4e from qemu
In db432672, we allow wide inputs for operations such as add.
However, in 212be173 and 3774030a we didn't do the same for
compare and multiply.
Backports commit 9a938d86b04025ac605db0ea9819e5896bf576ec from qemu
Opcodes are added for scalar and vector shifts, but considering the
varied semantics of these do not expose them to the front ends. Do
go ahead and provide them in case they are needed for backend expansion.
Backports commit d0ec97967f940bbc11dced83422b39c224127f1e from qemu
