Merge #8443 #8446

8443: Rewrite `#[derive]` removal code to be based on AST r=jonas-schievink a=jonas-schievink

We now remove any `#[derive]` before and including the one we want to expand, in the `macro_arg` query.

The same infra will be needed by attribute macros (except we only remove the attribute we're expanding, not any preceding ones).

Part of https://github.com/rust-analyzer/rust-analyzer/issues/8434 (doesn't implement the cfg-expansion yet, because that's more difficult)

8446: Undo path resolution hack for extern prelude r=jonas-schievink a=jonas-schievink

Reverts the change made in https://github.com/rust-analyzer/rust-analyzer/pull/7959

We don't populate the extern prelude for block DefMaps anymore,
so this is unnecessary

bors r+

Co-authored-by: Jonas Schievink <[email protected]>