[AArch64] Add support for legacy AArch32 NEON scalar shift by immediate
instructions.  This patch does not include the shift right and accumulate
instructions.  A number of non-overloaded intrinsics have been remove in favor
of their overloaded counterparts.
[AArch64] Tests for legacy AArch32 NEON scalar shift by immediate instructions.
A number of non-overloaded intrinsics have been replaced by thier overloaded
counterparts.