[DAGCombine] Generalize the case (add (or x, c1), c2) -> (add x, (c1 + c2))

[DAGCombine] Generalize the case (add (or x, c1), c2) -> (add x, (c1 + c2))

Reviewers: arsenm

Subscribers: sdardis, wdng, hiraditya, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, ecnelises, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D81708