[DAGCombiner] Transform (zext (select c, load1, load2)) -> (select c, zextload1, zextload2)

If extload is legal, following transform
    (zext (select c, load1, load2)) -> (select c, zextload1, zextload2)
can save one ext instruction.

Differential Revision: https://reviews.llvm.org/D95086

GitOrigin-RevId: 66f2d09ebf8d81d019a5524cdc5e7f88acbb7504
2 files changed