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

[Steven Johnson via cfe-commits]

steven-johnson wrote:

> We're trying wasm now.

This looked promising in our GitHub tests, but for reasons that aren't clear (yet), ~everything compiled this way inside google3 resulted in linker errors (missing symbols).

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