10703: internal: Don't check items for macro calls if they have no attributes r=Veykril a=Veykril
Turns out when highlighting we currently populate the Dynmaps of pretty much every item in a file, who would've known that would be so costly...
Shaves off 250 ms for the integrated benchmark on `rust-analyzer/src/config.rs`.
We are still looking at a heft `154ms - descend_into_macros (2190 calls)` but I feel like this is slowly nearing towards just call overhead.
bors r+
Co-authored-by: Lukas Wirth <lukastw97@gmail.com>