[aotinductor] Migrate fuse_split_linear_add from dper_pass to AOTI based on predispatch IR (#118983)
Summary: As titled. Added support of fuse_split_linear_add in pregrad passes based on predispatch IR
Test Plan: TORCH_LOGS=inductor,aot buck2 run mode/opt mode/inplace caffe2/test/inductor/fb:test_split_cat_fx_passes_aten_fb
Differential Revision: D53302168
Pull Request resolved: https://github.com/pytorch/pytorch/pull/118983
Approved by: https://github.com/kflu, https://github.com/chenyang78
