Currently, getIntImmCost returns TCC_Free for almost all intrinsics.
For most AArch64 specific intrinsics however, it looks like integer
constants cannot be folded into most of them (at least the ones I checked).
Unless we know that we can fold integer operands with the intrinsic, we
handle more cases correctly by returning the cost to materialize the
immediate than return TCC_Free.
Reviewers: SjoerdMeijer, dmgreen, t.p.northover, ributzka
Reviewed By: SjoerdMeijer
Differential Revision: https://reviews.llvm.org/D70669
93c8235702