Adapt the declarations of `svpattern` and `svprfop` to the most recent
one defined in section "5. Enum declarations" of the SVE ACLE
specifications [1].
The signature of the intrinsics using these enums have been changed
accordingly.
A test has been added to make sure that `svpattern` and `svprfop` are
not typedefs.
[1] https://developer.arm.com/documentation/100987/latest, version
00bet6
Reviewed By: joechrisellis
Differential Revision: https://reviews.llvm.org/D91333
Francesco Petrogalli