Implementation

[inkreasing]

No description provided.

[inkreasing]

@cjappl don't know if you want to look at everything.

First commit should be no functional change and just enabled me to later add more detailed sanitizer information.

Second commit actually adds rtsan in the parser, the existing checks for the sanitizer setting and the codegen backend.

Third commit is "optional". It adds a warning if someone uses rtsan with async functions, which doesn't really work. I don't know if the rust project actually wants this, so i keep the seperate commit.

[cjappl]

Nice, looks reasonable to me, about what I would expect (without digging into the dirty details)

Thanks