[clang] [llvm] Finish deleting the le32/le64 targets (PR #98497)

[Fangrui Song via cfe-commits]

https://github.com/MaskRay approved this pull request.

LGTM! That partial Le32/Leb64 restore was to give Halide some time. 

https://github.com/llvm/llvm-project/pull/98497