Better sanitize attr diagnostic

[luca3s]

While working on a new sanitizer i noticed that the error messages here could be better.
This now differentiates between a wrong / nonexisting sanitizer and a wrong / nonexisting value for a valid sanitizer.

This is my first time doing a PR to rustc, so i could have missed something.

[luca3s]

I would like for this to only mark the "bogus" part. I couldn't figure out how to get the correct span for that.

[rustbot]

r? @davidtwco

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[rustbot]

Some changes occurred in compiler/rustc_codegen_ssa

cc @WaffleLapkin

[jdonszelmann]

r? @jdonszelmann

[jdonszelmann]

@luca3s these errors would also be fixed by porting the attribute to the new parsing infrastructure. let me know if you'd be interested in doing that. If not, we could just merge this now and me or someone else will soon replace the code here. Alternatively we could close and again let me or someone else look at a new parser for this attribute soon.

[jdonszelmann]

actually, it's easier than that. I've just written the code to port sanitize already :). Feel like giving that a review? I'm sorry for taking your idea but I think this is a better permanent solution. Thanks for finding this in any case <3

[luca3s]

No Problem :) Do you have a link to that PR?

[jdonszelmann]

I'm just running the tests on my version, I'll link it in just a sec

[jdonszelmann]

#145670