Rollup merge of #142271 - workingjubilee:fn-ptrs-have-two-different-lints, r=RalfJung

compiler: fn ptrs should hit different lints based on ABI

I was looking closer at the code for linting on ABIs and realized a mistake was probably made during rebase or review. I think that for function pointers in the HIR, the lint that fires should probably depend on the ABI we encountered, e.g. if it's on the newly-deprecated set of ABIs or not. This will be slightly confusing for a little bit, but I think we can do more to reduce that confusion by switching `unsupported_fn_ptr_calling_conventions` to a hard error.

r? ``@RalfJung``

Author: fmease