[llvm] [x86] Enable indirect tail calls with more arguments (PR #137643)

[Reid Kleckner via llvm-commits]

https://github.com/rnk commented:

Nice! The comments say to me this should be safe, but I'm honestly not sufficiently confident that I can read the SDAG logic well enough to know that it's correct. I would appreciate it if one of the other reviewers can take a look if they have time.

One thing you could do to build more confidence in the meantime would be to add more negative tests, like `load ; store ; call load`, perhaps substituting in other oddball memory clobbering write operations. Or just point at this this test if it exists.

https://github.com/llvm/llvm-project/pull/137643