Auto merge of #144841 - cjgillot:typeck-no-attrs, r=davidtwco

Access less HIR attributes from typeck

Typeck relies on attributes to modify its own behaviour. This is a problem, as this means that `typeck(some function)` may depend on the span and doc-comments of many other functions.

This PR attempts to reduce such accesses to attributes. This yields to a sizeable perf improvement: rust-lang/rust#144841 (comment)

Fixes rust-lang/rust#124352

Author: bors