[RISCV][NFC] Add Test for (select (or B1, B2), X, Y)

Summary:
As shown, LLVM is keen to avoid logic and introduce selects (in DAGCombiner, and
other places). This leads to control flow on RISC-V which we should attempt to
avoid.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D79267