[DAGCombine] Hoist shifts out of a logic operations tree.

[DAGCombine] Hoist shifts out of a logic operations tree.

Hoist and combine shift operations from logic operations tree:
logic (logic (SH x0, s), y), (logic (SH x1, s), z)  --> logic (SH (logic x0, x1), s), (logic y, z)

The transformation improves code generated for some cases related to the issue https://github.com/llvm/llvm-project/issues/49541.

Correctness:
https://alive2.llvm.org/ce/z/pVqVgY
https://alive2.llvm.org/ce/z/YVvT-q
https://alive2.llvm.org/ce/z/W5zTBq
https://alive2.llvm.org/ce/z/YfJsvJ
https://alive2.llvm.org/ce/z/3YSyDM
https://alive2.llvm.org/ce/z/Bs2kzk
https://alive2.llvm.org/ce/z/EoQpzU
https://alive2.llvm.org/ce/z/Jnc_5H
https://alive2.llvm.org/ce/z/_LP6k_
https://alive2.llvm.org/ce/z/KvZNC9

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D131189